fully-grown Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition adjective. completely developed or matured in size. Example Sentence The puppy is now fully-grown. More Example Sentences A fully-grown dog needs more exercise. Synonyms mature; adult; developed Antonyms immature; underdeveloped; young Hear It! Say It! Write It! fully-grown Switch to cursive Start Share with your friends: