Sturdy, strapping (5)
I believe the answer is:
burly
This clue is a double definition.
'sturdy' is the first definition.
(thesaurus)
'strapping' is the second definition.
(I know that strapping can be written as burly)
(Other definitions for burly that I've seen before include "Beefy" , "Big and sturdy" , "Stocky" , "Sturdily built" , "Strongly and heavily built" .)