1560-70; < Latinvicissitūdō, equivalent to viciss(im) in turn (perhaps by syncope < *vice-cessim; vice in the place of (see vice3) + cessim giving way, adv. derivative of cēdere to go, proceed) + -i--i--tūdō-tude
1560s, from Middle French vicissitude (14c.), from Latin vicissitudinem (nominative vicissitudo) "change," from vicissim "changeably, in turn," from vicis "a turn, change" (see vicarious). Related: Vicissitudes.