to make (a person) uncertain, doubtful, or hesitant; confuse; puzzle
to make intricate or complicated; make confusing or hard to understand: to perplex an issue
Origin:
< ME perplex, perplexed < MFr perplexe < L perplexus, entangled, confused, involved < per, through + plexus, pp. of plectere, to twist, plait: see ply