agonise Get Printable Handwriting (ag-o-nise) 3 syllables Learn It! Spelling Test Definition verb. to make convulsive efforts; struggle to be in agony or great pain; feel anguish Chiefly British. Example Sentence He would agonise for months over his lost pet. Synonyms agonise; pain; anguish; hurt Antonyms cheerful Share with your friends: