Synonyms of conundrum

1 Syllable
sphinx, why, trick
2 Syllables
thrillers, thriller, stumper, rebus, poser, stumpers, teasers, sphinxes, teaser, puzzler, sphinges, puzzlers, riddle, problem, riddling, chillers
3 Syllables
brain-teaser, mystery, enigma, whodunit, braintwister, brainteaser, mindboggler, mind-twister, mysteries, puzzlement, brain-twister, mind-boggler
4 Syllables
perplexity, abstruseness, perplexities
5 Syllables
abstrusenesses, inscrutableness, mystification
6 Syllables
inscrutability