Group helping to make house tidy (3)
I believe the answer is:
set
'group' is the definition.
(both can mean a collection)
'helping to make house tidy' is the wordplay.
'helping to make' indicates a hidden word.
'SET' can be found hidden inside 'house tidy'.
(Other definitions for set that I've seen before include "Arrange; a party" , "become firm" , "Series of tennis games" , "exclusive party" , "Fix in place; similar group" .)