Definition of "infirm" in English

adjective

1. Weak or ill, not in good health.

   • He was infirm of body but still keen of mind, and though it looked like he couldn't walk across the room, he crushed me in debate.

2. Irresolute; weak of mind or will.

3. Frail; unstable; insecure.

verb

1. To contradict, to provide proof that something is not.

   • The thought is that you see an episode of observation, experiment, or reasoning as confirming or infirming a hypothesis depending on whether your probability for it increases or decreases during the episode.