flummox
Flummox (verb) means to leave someone completely confused or baffled.
Etymology
Uncertain, probably risen out of a British dialect (OED finds candidate words in Herefordshire, Gloucestershire, southern Cheshire, and Sheffield). The formation seems to be onomatopœic, expressive of the notion of throwing down roughly and untidily. [OED]. First use appears c. 1837 in the writings of Charles Dickens.