Tag, key or chip, say (3)

I believe the answer is:

mar

(Other definitions for mar that I've seen before include "Make imperfect" , "Oh dear!" , "Spoil or deface" , "when spring growth starts?" , "Spoil something" .)

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.