Be obliged to work with hands when caught (4)
I believe the answer is:
need
'be obliged' is the definition.
(thesaurus)
'work with hands when caught' is the wordplay.
'work with hands' becomes 'knead' (as in kneading dough).
'when caught' indicates a 'sounds like' (homophone) clue.
'knead' is a homophone of 'NEED'.
'to' acts as a link.
(Other definitions for need that I've seen before include "What's lacking" , "Rely on" , "'miss'" , "must have results!" , "destitute state" .)