Grade 5 watchful Get Printable Handwriting (watch-ful) 2 syllables Rhymes Learn It! Spelling Test Definition adjective. vigilant or alert; closely observant Example Sentence The mother was watchful as her son cooked. Synonyms alert; attentive; aware; careful; cautious Antonyms ignore Rhymes Two Syllable Rhymes (1) watchful Share with your friends: