"Feather in the cap" is a phrase that refers to an accomplishment or achievement that makes someone proud. There are many synonyms for this phrase, including "crowning achievement", "pinnacle of success", "triumph", "accomplishment", "milestone", "badge of honor", "victory", "coup", and "success story". These phrases all convey a sense of pride and recognition for a significant achievement. Whether it's a personal accomplishment or a professional milestone, having a "feather in the cap" is a testament to one's hard work and dedication. So if you've achieved something great, whether big or small, consider it a "feather in your cap" and take a moment to celebrate your success.