Relating to a single occasion (3-4)

I believe the answer is:

one-time

'relating to a single occasion' is the definition.
(I've seen this before)

This is all the clue.

(Other definitions for one-time that I've seen before include "Former" , "Relating to a single occasion" .)

I've seen this clue in The Guardian.

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.