stumper Synonyms

puzzler tough proposition trouble teaser successor stickler sticker sphinx seeker secret riddle question twister why tough one fishing question whistle-stopper tough nut to crack brainteaser closed book toughie brain-teaser write-in jigsaw puzzle quandary puzzlement puzzle enigma dilemma difficulty cryptogram crux crosslet conundrum claimant challenge case eyeleteer floorer grabber problem poser petitioner perplexity paradox mystification mystery matter knot issue