get the wind knocked out of (one)

To have one's diaphragm spasm and contract following a sudden force or impact, resulting in a temporary inability to breathe properly. A: "I heard that a car knocked you off your bicycle earlier. Are you OK?" B: "Yes, thankfully I just got the wind knocked out of me. It could have been a lot worse." He got the wind knocked out of him from the blow to his stomach. I know, honey, it's scary to fall and get the wind knocked out of you like that. But you're going to be OK, I promise.