Narrow opening for mail (4)

I believe the answer is:

slot

(Other definitions for slot that I've seen before include "Opening (for coins)" , "Hole for money" , "Opening for coin or TV programme" , "Scheduled time - hierarchical position" , "Scheduled time -- aperture for coins" .)

I've seen this clue in the Newsday.

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.