diadem Get Printable Handwriting (di-a-dem) 3 syllables Rhymes Learn It! Spelling Test Definition noun. 1.a crown or headband symbolizing royal status; 2.the authority or dignity of royalty. Example Sentence The queen wore a diamond diadem. Synonyms crown; royal headband; headpiece with jewels Antonyms watch Rhymes Three Syllable Rhymes (1) diadem Share with your friends: