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.

1640s; see fork (n.) + -ful.

also fork-lift, by 1953, short for fork-lift truck (1946), from fork (n.) + lift (n.).

1754, in reference to anatomical structures, from French fourchette, diminutive of fourche "a fork" (see fork (n.)).

"fork for lifting and pitching" (hay, etc.), commonly with a long handle and two prongs, mid-14c., altered (by influence of pichen "to throw, thrust;" see pitch (v.1)) from Middle English pic-forken (c. 1200), from pik (see pike (n.2)) + fork (n.). The verb, "to lift or throw with a pitchfork," is attested from 1837.

1909, from spoon (n.) + fork (n.).

two-pronged steel instrument designed to produce a tone of a particular pitch when struck, by 1776; see tuning (n.) + fork (n.). Supposedly invented by John Shore (d.1753), royal trumpeter.

[Shore] was a man of humour and pleasantry, and was the original inventor of the tuning-fork, an instrument which he constantly carried about him, and used to tune his lute by, and which whenever he produced it gave occasion to a pun. At a concert he would say, "I have not about me a pitch-pipe, but I have what will do as well to tune by, a pitch-fork." [Sir John Hawkins, "A General History of the Science and Practice of Music," London, 1776]

A similar device was the tuning-cone, a hollow brass cone used in tuning metal organ pipes.