Moved us to check most strapping (8)
I believe the answer is:
stoutest
'most strapping' is the definition.
Both the answer and definition are superlative adjectives. Maybe there's a link between them I don't understand?
'moved us to check' is the wordplay.
'moved' is an anagram indicator.
'check' becomes 'test' (as in testing or checking something works).
'us'+'to'='usto'
'usto' is an anagram of 'stou'.
'stou'+'test'='STOUTEST'
Can you help me to learn more?
(Other definitions for stoutest that I've seen before include "Most strong" , "Most solidly built or resolute" , "Sturdiest or fattest" , "Most enduring" , "Most sturdy or fattest" .)