swallow one's pride
Humble oneself, as in She decided to swallow her pride and apologize. This idiom employs swallow in the sense of “refrain from expressing,” a usage dating from the early 1600s.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.