to give up power or control: The other side is not ready to negotiate, but we won't knuckle under to their demands.

What does it mean to knuckle under someone?

intransitive verb. : give in, submit.

Will not knuckle under pressure meaning?

knuckle under, to

To give in under pressure; to admit defeat. ... The verb to knuckle originally meant “to bend down” or “stoop” (probably from the joint's bending), and by extension “to comply with” or “submit to”—it was so used from the 1700s on.