Something that's gaudy is showy, bright and definitely tacky. So think twice about that gaudy rainbow-colored suit and shiny gold shoes ensemble.
Gaudy is an adjective that means "ostentatious" — in other words, flashy and in your face, and not in a good way. Someone in a gaudy outfit is probably trying too hard to be cool and stylish. Gaudy evolved from the Middle English gaud “deception, trick” in the 1520’s. That word, in turn, came from gaudi, used to describe a “large, ornamental bead in a rosary.”