Verb
consent reluctantly
Source: WordNetHans had courage to burn. If he had been willing to knuckle under to the Nazis he would have stayed at Kaiser Wilhelm Institute. But Hans was a scientist. He wouldn't trim his notion of truth to fit political gangsters. Robert A. Heinlein
I will be ashamed the day I feel I should knuckle under to social-political pressures about issues and research I think are important for the advance of scientific knowledge. Arthur Jensen