Crossword Genius

Cause for much boasting (3)

Ross

I believe the answer is:

ego

(Other definitions for ego that I've seen before include "Sense of self, conceit" , "number one" , "Inflated pride" , "One's image of oneself" , "Self-esteem or self-importance" .)

I've seen this clue in The New York Times.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.