knack /næk/noun 3verb 2forms 3 noun3 •A readiness in performance; aptness at doing something.These men had some uncanny knack of knowing when the steel was right, and like many such things, it just could not be put into a textbook on the subject. — 1945 •Something performed, or to be done, requiring aptness and dexterity. •A petty contrivance; a toy. verb2 •To speak affectedly. •(dialect, no longer used) To crack; to make a sharp, abrupt noise; to chink.If they hear the Beads knack upon each other, that's enough. — 1674 formsknacked · knacking · knacks