Shut a tin-opener in a cupboard (6)
I believe the answer is:
closet
'cupboard' is the definition.
(type of cupboard)
'shut a tin-opener' is the wordplay.
'shut' becomes 'close' (synonyms).
'opener' indicates taking the first letters.
The initial letter of 'tin' is 't'.
'close'+'t'='CLOSET'
'in a' is the link.
(Other definitions for closet that I've seen before include "place to store gear" , "Small room or wardrobe" , "Private room; cupboard" , "US press for clothing" , "A small room or cupboard" .)