0 past simple and past participle of bonk
1 to hit someone or something, not very hard:
2 to have sex with someone:
"I never bonked him," she claimed.
3 to reach a point where you have no energy left and feel you cannot continue physical exercise, especially when riding a bicycle or running:
Fat and protein slow digestion, so any carbs you get from beef jerky won't help your muscles 'til you've already bonked.
Emma has to be fed energy gels when she bonks after checkpoint one.
He led the race to the final 5 meters where he bonked and dropped from first to seventh place.
Thomson badly bonked on the day's last climb, and wound up being passed by escapees from the main peloton.