Yours, Etc.: Origins and Uses of 8 Sign-Offs
1847, applied to the apes (Troglodytes gorills) by U.S. missionary Thomas Savage, from Greek gorillai, plural of name given to wild, hairy people in a Greek translation of Carthaginian navigator Hanno's account of his voyage along the N.W. coast of Africa, c.500 B.C.E. Allegedly an African word.
In its inmost recess was an island similar to that formerly described, which contained in like manner a lake with another island, inhabited by a rude description of people. The females were much more numerous than the males, and had rough skins: our interpreters called them Gorillae. We pursued but could take none of the males; they all escaped to the top of precipices, which they mounted with ease, and threw down stones; we took three of the females, but they made such violent struggles, biting and tearing their captors, that we killed them, and stripped off the skins, which we carried to Carthage: being out of provisions we could go no further. [Hanno, "Periplus"]Of persons perceived as being gorilla-like, from 1884.