feather in one's cap, a

An accomplishment or achievement that one takes pride in. If this clinical trial is successful, it will be a real feather in her cap. I can't wait until I'm named valedictorian— it's such a feather in my cap!

Fig. an honor; a reward for something. Getting a new client was really a feather in my cap. John earned a feather in his cap by getting an A in physics.

An act or deed to one's credit; a distinctive achievement. For example, Getting all three factions to the bargaining table would be a feather in his cap. This expression alludes to the practice of putting a feather on a soldier's cap for every enemy he kills, an early practice of some Native American tribes and many other peoples. [Early 1600s]

An act or deed to one's credit; a distinctive achievement.

A special honor or achievement. This term comes from the custom of numerous peoples—American Indian tribes, Turks, Himalayan peoples, among others—of placing a feather in a soldier’s cap for every enemy he kills. The term began to be used figuratively by the early seventeenth century and was a cliché by the time Laurence Sterne wrote, “The feather put into his cap of having been abroad” (Tristram Shandy, 1761–67).