Dressing puts years on group (7)
I believe the answer is:
bandage
'dressing' is the definition.
(dressing for a wound)
'years on group' is the wordplay.
'years' becomes 'age' (period of many years).
'on' means one lot of letters go next to another.
'group' becomes 'band' (band can mean a group of people).
'age' put after 'band' is 'BANDAGE'.
'puts' is the link.
(Other definitions for bandage that I've seen before include "Cloth to cover injuries" , "Dressing for wounds" , "medical cover" , "Material for wound or injury" , "First-aid item" .)