Complicate
early 17th century (in the sense ‘combine, entangle, intertwine’): from Latin complicat- ‘folded together’, from the verb complicare, from com- ‘together’ + plicare ‘to fold’.
wiktionary
Borrowed from Latin complicatus, past participle of complicare(“to fold together”), from com-(“together”) + plicare(“to fold, weave, knit”); see plaid, and compare complex.
etymonline
complicate (v.)
1620s, "to intertwine," from Latin complicatus "folded together; confused, intricate," past participle of complicare "to involve," literally "to fold together," from com "with, together" (see com-) + plicare "to fold, weave" (from PIE root *plek- "to plait"). Meaning "to make more complex or intricate" is recorded from 1832, from earlier sense "to combine in a complex way" (17c.). Related: Complicated; complicating.