The English word “butterfly” traces back to the Old English “buttorfleoge,” a compound of “buttor” (butter) and “fleoge” (fly), but why anyone decided to name these insects after butter remains genuinely uncertain. Multiple theories have circulated for centuries, none of them settled. The naming puzzle gets even stranger when you look at what other languages call the same insect, because almost no two linguistic traditions landed on the same idea.
The Butter Problem
The most straightforward explanation is also the simplest: many of the butterflies commonly seen across northern Europe are yellow. The brimstone butterfly, one of the first species to appear each spring in England and continental Europe, is a vivid butter-yellow. Early English speakers may have simply named the whole group after the color of the most conspicuous members they encountered. This is sometimes called the “butter-colored fly” theory, and it has the advantage of requiring no elaborate backstory.
A second theory leans on folklore. In parts of medieval Europe, butterflies were associated with witches who supposedly took the form of winged insects to steal butter and milk. The German dialect word “Buttervogel” (butter-bird) and the Dutch “botervlieg” both echo this superstition. Under this interpretation, “butterfly” is less a description of color and more a shorthand for a creature linked to dairy thievery in the popular imagination.
A third, less poetic explanation points to butterfly excrement. Some species, particularly the pale-winged pierids, produce yellowish droppings. The Dutch word “boterschijte,” which translates roughly to “butter-excrement,” reflects this observation directly. Whether English speakers had the same association when they coined “buttorfleoge” is anyone’s guess.
You will sometimes hear people claim that “butterfly” is actually a garbled version of “flutter-by,” reversed over centuries of casual speech. This is a folk etymology with no historical support. Linguists have found no evidence of a transitional form between “flutter-by” and “butterfly,” and the Old English compound “buttorfleoge” is attested in manuscripts that predate any plausible flip. It is a satisfying story and almost certainly wrong.
Why the Yellow Connection Runs Deep
The butter-color theory gains some indirect support from biology. The Pieridae family, which includes brimstones, cabbage whites, and sulphurs, is one of the most widespread butterfly groups in Europe and North America. Many pierid species get their yellow, orange, and white wing colors from pterin pigments rather than the structural coloration that produces iridescence in other butterfly families. Research on pierid wings has identified specific pigments responsible for these hues: leucopterin produces white in species like the cabbage white, while xanthopterin and erythropterin generate the yellows and oranges seen in sulphur butterflies and the wing tips of some males.1PubMed. Colors and pterin pigmentation of pierid butterfly wings
These butter-yellow pierids are not rare tropical specialties. They are the butterflies you see in gardens, fields, and roadsides across temperate Europe, which means they would have been the butterflies most familiar to Old English speakers. If you were a farmer in early medieval England and the first winged insects of spring were bright yellow, naming the group after butter is not much of a leap.
What Other Languages Chose Instead
One of the most revealing things about butterfly naming is how wildly it varies across languages. If the connection to butter were self-evident, you would expect other cultures to land on something similar. They mostly did not.
French uses “papillon,” which descends from the Latin “papilio.” The Latin word itself has no clear further etymology. It may be related to an older root meaning “to tremble” or “to flutter,” but the trail runs cold in pre-Latin. Spanish went in a completely different direction with “mariposa,” which some etymologists trace to a phrase invoking the Virgin Mary, possibly a contraction of “María, pósate” (Mary, alight), spoken as a kind of charm. Russian uses “babochka,” a diminutive related to “baba,” meaning old woman or grandmother, possibly reflecting a folk belief that the souls of deceased older women returned as butterflies.
German chose “Schmetterling,” derived from a Slavic-influenced word for cream or sour cream. This is interesting because it parallels the English dairy connection, though the specific dairy product differs. It suggests that across northern and central Europe, something about butterflies reminded people of rich, pale-yellow foods, whether that was the insect’s color, its behavior around kitchens, or the folk associations that grew up around both.
Greek stands out for a different reason. The classical Greek word for butterfly is “psyche,” which also means soul or spirit. This double meaning shaped centuries of art and mythology, most famously in the story of Psyche and Eros (Cupid). The association between butterflies and the human soul was not just a Greek idea; it appeared across many ancient cultures, but the Greek language embedded it directly into the name.
The Scientific Name Tells a Different Story
When Carl Linnaeus formalized the classification of insects, the order containing butterflies and moths received the name Lepidoptera. The word comes from ancient Greek: “lepis” meaning scale and “pteron” meaning wing.2IntechOpen. Introductory Chapter: Lepidoptera So the scientific name translates to “scale-winged,” which is a straightforward physical description rather than a cultural association. If you have ever touched a butterfly wing and noticed the fine powder that rubs off on your fingers, those are the microscopic scales the name refers to.
The choice of “scale-winged” reflects what makes butterflies and moths genuinely distinctive among insects. Plenty of insects fly, plenty are colorful, and plenty visit flowers. But the overlapping rows of tiny scales that cover their wings, each one a flattened modified hair, are unique to the Lepidoptera. Those scales are what produce both the pigment-based colors of pierids and the structural iridescence of morpho butterflies and swallowtails. The scientific name, unlike the English common name, zeroes in on the feature that actually defines the group.
Moths Got a Different Deal
English makes a sharp distinction between butterflies and moths that many languages blur or skip entirely. “Moth” comes from Old English “moþþe,” which originally referred to the larval stage, the caterpillar that eats through wool and stored food. The adult flying form inherited a name that was really about the destructive grub. This means that in English, “butterfly” was named for how the adult looks while “moth” was named for what the larva does, two completely different naming strategies for insects that belong to the same order.
In many other languages, the distinction barely exists. French “papillon” covers both butterflies and moths, with “papillon de nuit” (night butterfly) used when people want to specify a moth. Japanese “chō” traditionally referred to both groups, with separate terms becoming common only under Western taxonomic influence. The hard line English draws between butterflies and moths is a cultural artifact, not a biological one. Taxonomically, “moth” is not even a coherent group; butterflies are essentially a subset of moths that evolved daytime activity and clubbed antennae.
Butterflies, Souls, and Medieval Symbolism
The Greek naming connection between butterflies and the soul was not a dead metaphor. It persisted through the Roman period and deep into the European Middle Ages. Medieval Christian manuscripts contain numerous illustrations of putti, small winged children, chasing or catching butterflies. These scenes draw on the pagan myth of Cupid and Psyche, where the butterfly represents the soul pursued by love. The survival of this essentially pagan motif in Christian religious texts is striking and shows how thoroughly the butterfly-as-soul association had embedded itself in European culture.3The Journal of the Lepidopterists’ Society. Chasing Butterflies in Medieval Europe
This symbolic tradition may have coexisted with the more mundane butter-related naming in the Germanic languages. Medieval Europeans could hold both ideas simultaneously: the butterfly as a practical farmyard creature associated with dairy and warm weather, and the butterfly as a potent symbol of the soul’s journey. The common English name stuck to the earthy, everyday side of that dual identity while the Greek-derived symbolism lived on in art and literature.
Why No Single Theory Has Won
Etymology is full of cases where the true origin of a word is simply lost. With “butterfly,” the problem is not a lack of theories but a surplus of plausible ones. The word is very old, appearing in written English well before anyone thought to record why they used it, and none of the competing explanations can be ruled out on purely linguistic grounds.
The butter-color theory is probably the most widely cited in modern dictionaries, partly because it requires the fewest assumptions. You see a yellow insect, you call it a butter-fly. But the dairy-theft folklore is well attested across Germanic cultures, and the excrement theory, while less charming, has a direct parallel in Dutch. It is entirely possible that the word caught on precisely because it worked on multiple levels: the color fit, the folklore fit, and the association stuck.
What we can say with confidence is that the name is Germanic in origin, it predates Middle English, and the “butter” component almost certainly refers literally to butter (the food product) rather than being a corruption of another word. Beyond that, honest dictionaries will tell you the rest is educated guessing.
Names That Came Later
Many of the butterfly names used in everyday English today are surprisingly recent. Common names like “painted lady,” “red admiral,” and “monarch” were assigned or popularized by naturalists in the 18th and 19th centuries, often reflecting the visual impression the butterfly made on a particular collector. “Monarch” was applied to the large orange North American migrating species, apparently because of its size and perceived majesty. “Red admiral” references the wing markings that someone thought resembled a naval flag.
Before this period of systematic common naming, people in English-speaking countries mostly just called them all butterflies, maybe specifying color or size in passing. The idea that each species deserves its own common name is a product of the same era that produced field guides, pinned specimen collections, and amateur natural history societies. These names often carry their own miniature etymology puzzles. “Cabbage white” is self-explanatory. “Swallowtail” describes the tail-like extensions on the hindwing. But “skipper,” used for a family of small, darting butterflies, comes from their erratic flight pattern, a name about behavior rather than appearance.
When Naming Reveals What People Noticed
The names that different cultures give butterflies are a window into what those cultures found most salient about the insects. English speakers in early medieval northern Europe apparently noticed the color, or the dairy association, or both. Greek speakers noticed the butterfly’s metamorphosis and linked it to the soul’s transformation. German and Dutch speakers, like the English, fixated on the dairy connection. Spanish speakers may have invoked a religious figure. Russian speakers saw an old woman.
None of these observations are wrong, exactly. Butterflies are yellow (some of them), they do undergo a dramatic transformation, they do hover around kitchens, and the fluttering flight of certain species could remind you of an elderly person’s halting movement. Each language selected one facet of the butterfly experience and froze it into a word. The English name just happens to have frozen the most puzzling facet, because nobody left a note explaining which specific butter connection they had in mind. If the brimstone butterfly had been red, or if butter had been white in early England, the word might have gone in a completely different direction, and this particular etymological mystery would not exist.