Pop group lodged in Cotswold mansion (3,3)
I believe the answer is:
old man
'pop' is the definition.
('old man' can be a synonym of 'pop')
'group lodged in cotswold mansion' is the wordplay.
'group lodged in' indicates a hidden word.
'OLD MAN' is hidden within 'cotswold mansion'.
(Other definitions for old man that I've seen before include "Master?" , "Senior citizen" , "Aged male as informal father" , "Husband (inf)" , "Husband - father - boss" .)