Grade 4 heaviest Get Printable Handwriting (heav-i-est) 3 syllables Learn It! Spelling Test Definition adjective. 1 having much weight or hard to lift; 2 of great size or amount; 3 causing great concern; very serious; 4 very sad; weighed down. Example Sentence Which player on the team is the heaviest? Synonyms fat; fleshy; deep; grave; keen; serious Antonyms light Share with your friends: