tickler Synonyms

difficult proposition puzzler stiletto skewer sickle scalpel reminder point memorandum machete lance thriller brain-teaser cliffhanger braintwister brain-twister awkward problem tickler file French tickler cruncher crossword Chinese puzzle chiller brainteaser knife difficulty case blade bewilderment bayonet argument anagram amuser ambiguity affair abstrusity challenge chaos charade cutter cryptogram crux convolution conundrum contention confusion concern complication complexity abstruseness