key Get Printable Handwriting (key) 1 syllables Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. a small metal object used to open locks. Example Sentence Jason unlocked the door with the key. OR That is a key point. More Example Sentences She used the key to unlock the door. Synonyms lock opener; guide; essential Antonyms lock Hear It! Say It! Write It! key Switch to cursive Start Share with your friends: