Obliged to be a servant, we hear (4)
I believe the answer is:
made
'obliged' is the definition.
(thesaurus)
'a servant we hear' is the wordplay.
'a servant' becomes 'maid' (maid is a type of servant).
'we hear' shows a homophone (sound like).
'maid' sounds like 'MADE'.
'to be' is the link.
(Other definitions for made that I've seen before include "Built" , "Produced" , "Constructed" , "Fabricated" , "Created" .)