It keeps the openers around (3,4)
I believe the answer is:
key ring
'it keeps the openers around' is the definition.
The definition suggests a singular noun which matches the answer.
This is all the clue.
Can you help me to learn more?
(Other definitions for key ring that I've seen before include "place for lockers" , "What may carry a fob" , "Gaoler's holder" , "Grey ink (anag)" , "a lot may hang on it" .)