amphibian

Amphibian is Greek twice over: amphi, "of both kinds," plus bios, "life" — something that lives a double life. The ph in both halves is the standard way Latin transliterated the Greek letter phi, and English kept it rather than writing the f it actually says. That single detail is enough to place the word: English had a perfectly serviceable f and declined to use it, which almost always means the word came through Greek.

The meaning has narrowed sharply. When English took the word in the 1630s it meant simply "having two modes of existence," and could also mean "of doubtful nature" — an insult as much as a description. Zoologists then used it for any animal at home in both water and on land, which swept in crocodiles, seals, beavers, walruses and hippopotamuses. Only in 1835 was it pinned down to the modern class sitting between fishes and reptiles, the creatures that begin life in water with gills and finish it on land.

amphibian
(adj.)
1630s, "having two modes of existence; of doubtful nature," from Greek
amphibia
, neuter plural of
amphibios
"living a double life," from
amphi
"of both kinds" (see
amphi-
) +
bios
"life" (from PIE root
*gwei-
"to live").
Formerly used by zoologists to describe any sort of animal at home on land and in the water, including crocodiles, walruses, beavers, seals, hippopotamuses; the restriction to the class of animals between fishes and reptiles with life cycles that begin in water and mature on land is from 1835.
also from 1630s

amphibian
(n.)
"one of the class of animals between fishes and reptiles, having gills and living in water in the early stage of life, later living on land," 1835; from
amphibian
(adj.).
Amphibia
was used in this sense from c. 1600.
also from 1835

← look up another word