Slightly outdo

ONEUP

To surpass someone by just a small margin, often in competition or achievement.

The clue "Slightly outdo" hints at the answer "ONEUP," which means to gain a slight advantage over someone. The wordplay comes from "one up," a phrase often used in games or competitions to describe being ahead by a small margin. It’s a straightforward definition with a casual tone, fitting the idea of narrowly surpassing another.