Grade 0 undoes Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition verb. to reverse the effect of something. Example Sentence He can not take off his shoes until he undoes his shoelaces. More Example Sentences He undoes the knot in the rope. Synonyms reverses; cancels; nullifies Antonyms executes; performs; enacts Hear It! Say It! Write It! undoes Switch to cursive Start Share with your friends: