Origin: 1400–50; late Middle English vocacio(u)n < Latin vocātiōn- (stem of vocātiō) a call, summons, equivalent to vocāt(us) past participle of vocāre to call (see -ate1) + -iōn--ion
early 15c., "spiritual calling," from L. vocationem (nom. vocatio), lit. "a calling," from vocatus "called," pp. of vocare "to call" (see voice). Sense of "one's occupation or profession" is first attested 1550s.