1. To make convulsive efforts; to struggle; to strive in physical exercise: The hikers were agonising in the hot sun as they were climbing up the high mountain.
2. To be in agony; to be in great pain: Susan agonized over the difficult decision that had to be made before making the final phone call.

Pertaining to severe concern or pain: Jill could understand the agonized worry and anxiety that her mother had regarding the health of her father.