What it names now
In living English a python is a large, nonvenomous constrictor of the family Pythonidae: snakes native mainly to Africa, Asia, and Australia that kill by coiling rather than by venom. A few species rank among the longest snakes on earth. Speakers also stretch the word to other bulky constrictors, and slang has used it for the penis. None of that zoological precision is original. The English name is a late transfer of a Greek monster’s name onto real tropical snakes.
The origin of the word python is a borrowing, not a native Germanic formation. English took it from Latin Python, itself from Greek Python, the serpent Apollo killed near Delphi.
How English first met the name
In Greek myth, Python was the earth-serpent of Delphi, sometimes pictured as a dragon, said to guard the omphalos, the stone treated as the navel of the world. In the usual story Apollo shot the creature and took over the oracle. The priestess there was called the Pythia, from Pytho, an older name of the Delphi district. Apollo himself was Pythian, and the Pythian Games were later explained as a rite after the killing.
English writers met the name as story long before they met the animal. Around 1390, in The Manciple’s Tale, Chaucer has Phoebus slay Phitoun the serpent as it lay sleeping in the sun. That spelling, with ph- and a French-looking ending, shows the word arriving through medieval French and Latin rather than as a restored Greek form. A classical-looking Python is recorded in English by 1548, in work associated with the schoolmaster Nicholas Udall. Later sixteenth-century use settles on the fabled serpent under that spelling. French has a parallel learned mythological form in the same century.
The same Greek stem also named a spirit of divination. In the Acts of the Apostles a slave girl is described as having a python spirit. Late Latin pythonissa, used in the Vulgate for the woman of Endor, yielded Middle English pythoness, earlier spelled phitonesse, for a female soothsayer. Latin python itself could mean soothsayer. In English those prophetic senses are older than any zoo label.
The place, the rotting, and the depths
Greek Python is usually tied to Pytho, the old name of Delphi. Past that point the trail splits, and the sources do not agree.
Ancient Greek tradition explained Pytho from a verb meaning to rot: after Apollo killed the serpent, the carcass decayed in the sun, and the district took a name from that decay. The Homeric hymn tradition offers that account. It may be a story invented to justify the place-name rather than a true derivation.
Another reconstruction links the name to a Proto-Indo-European root meaning hollow, deep, or the depths, in an extended form used of monsters that inhabit those depths. Dictionaries that print both options treat them as uncertain. There is no prefix or suffix to unpack in English: python is the whole Greek-Latin name, borrowed as a unit.
Related words in modern European languages — French python, Dutch python, German Python, Italian pitone, Spanish pitón, Russian piton — are the same learned borrowing, not separate inherited cousins. If the deep-root reconstruction is right, English deep and dive would sit on a distant shared ancestor, but that remains a hypothesis, not a demonstration.
From monster to genus
Once the Delphic Python was familiar, the name loosened onto any very large snake. French herpetology then pinned it to living animals. In 1803 François Marie Daudin established the genus Python. The type species is the Indian rock python, which Linnaeus had earlier placed in Coluber. English dictionaries date the common-noun zoological sense to 1836, following French use. The family Pythonidae is the later scientific frame around that genus: Old World constrictors that include some of the longest snakes alive.
The transfer was classicizing, not a claim that African or Asian snakes were the Delphic guardian. Naturalists needed a Latin label for huge Old World constrictors, and the myth already supplied a famous serpent.
A dating worth keeping
A later namesake is easy to confuse with the animal. The programming language Python, begun by Guido van Rossum in the late 1980s, takes its name from the British comedy troupe Monty Python, not from the snake, though the troupe’s name uses the same English word. That coinage does not rewind the zoological history.
The sequence that stays useful is this: English had the Delphic serpent, under a medieval spelling, by Chaucer’s time; it had a restored classical Python by the mid-1500s; French science put the name on a genus in 1803; and everyday English did not mean a living tropical constrictor until the nineteenth century.