The , 1961 stage play by Ann Jellicoe (5)

I believe the answer is:

knack

(Other definitions for knack that I've seen before include "Ability, facility" , "Instinctive skill" , "Special ability" , "Skill in doing something" , "Hang" .)

I've seen this clue in The Mirror.

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.