2.knuckle underphrasal verbphr v informalOBEYto accept someone’s authority or orders although you do not want to 屈服;认输
Examples from the Corpus
knuckle• But he kept his anger under control and vowed to knuckle down and fight for a first-team future.• No attempts made to knuckle down and smarten up.• Malespeaker I think we've got to knuckle down and work hard.• Social workers and their managers are clearly ready to knuckle down to the task of making the policy work for users.• Mollified, if not entirely convinced, Vincent went back to Mauve and tried hard to knuckle down.• Some coachesknuckle under to that.