designate adj.

late 14c., designacioun, "notation, representation, action of pointing or marking out," from Old French designacion or directly from Latin designationem (nominative designatio) "a marking out, specification," noun of action from past participle stem of designare "mark out, devise, choose, designate, appoint," from de "out" (see de-) + signare "to mark," from signum "identifying mark, sign" (see sign (n.)).

Sense of "nomination, a selecting and appointing" is from c. 1600. Meaning "a descriptive name" which designates, originally especially an addition to a name of a title, profession, trade, or occupation, is from 1824.

1868, "appointed or nominated but not yet installed," past-participle adjective from designate (v.). The baseball designated hitter "substitute named before the start of a game to hit for the pitcher" was introduced in the American League in 1973; it soon gave wide figurative extension to designated, as in designated driver (by 1985).