riddle Synonyms

diffuse enigma permeate penetrate pervade brain-teaser conundrum imbue interpenetrate screen stumper stickler trepan transpierce teaser strain strainer suffuse striate steganography sphinx reticle reticulation riddled riddling screening secrecy secret sieve sifted sift sifter refinery sorter trephine twister uncipher koan lacework discolour brattle cut through check off meshwork grillwork speak in tongues whodunit closed book brainteaser pick-off