Lunar dark spot (4)

I believe the answer is:

mare

(Other definitions for mare that I've seen before include "Ream (anag)" , "For classicists, sea" , "Adult female zebra" , "Female quadruped" , "A night-time strangler" .)

I've seen this clue in the LA 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.