1. to announce one’s candidacy for election to office; to issue a challenge

1. Dave threw his hat into the ring today. He’s running for class secretary.

2. Jane wanted to run for treasurer, so she tossed her hat into the ring.

3. I won’t throw my hat into the ring until the last minute.

4. In order to get as much publicity for her campaign for mayor of the city as possible, Dr. Smith tossed her hat into the ring early.