know-it-all Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. someone who thinks he knows everything and refuses to accept advice or information from others Example Sentence My brother is a know-it-all. Spelled with a hyphen. Synonyms walking encyclopedia; wise guy; brain; smart aleck Antonyms humble; modest Hear It! Say It! Write It! know-it-all Switch to cursive Start Share with your friends:
