early 15c., from Middle French complication, from Latin complicationem (nominative complicatio), noun of action from past participle stem of complicare "to fold together, fold up, roll up," from com- "together" (see com-) + plicare "to fold, weave" (see ply (v.1)). Meaning "something that complicates" first recorded 1903.[complication etymology, complication origin, 英语词源]