Strapping lad initially housed in part of Gt Manchester (5)
I believe the answer is:
burly
'strapping' is the definition.
('burly' can be a synonym of 'strapping')
'lad initially housed in part of gt manchester' is the wordplay.
'initially' suggests taking the first letters.
'housed in' is an insertion indicator.
'part of gt manchester' becomes 'bury'.
The initial letter of 'lad' is 'l'.
'l' inserted within 'bury' is 'BURLY'.
(Other definitions for burly that I've seen before include "Sturdily built" , "Strong and heavy in build" , "Big and thickset" , "Muscular and heavily built" , "Stocky" .)