c. 1300, "branched or divided in two parts," past-participle adjective from fork (v.). Of roads from 1520s; from 1550s as "pointing more than one way." In 16c.-17c. sometimes with a suggestion of "cuckold," on the notion of "horned." Forked tongue as a figure of duplicitous speech is from 1885, American English. Double tongue in the same sense is from 15c.
Table forks are said to have been not used among the nobility in England until 15c. and not common until early 17c. The word is first attested in this sense in English in an inventory from 1430, probably from Old North French forque (Old French furche, Modern French fourche), from the Latin word. Of rivers, from 1753; of roads, from 1839. As a bicycle part from 1871. As a chess attack on two pieces simultaneously by one (usually a knight), it dates from 1650s. In old slang, forks "the two forefingers" is from 1812.