Maybe the right sort of wife (robust) (5)
I believe the answer is:
whale
'maybe the right sort' is the definition.
(right whale is a type of whale)
'wife robust' is the wordplay.
'wife' becomes 'w'.
'robust' becomes 'hale' (in good health).
'w'+'hale'='WHALE'
'of' acts as a link.
(Other definitions for whale that I've seen before include "Moby-Dick" , "Large animal" , "Large marine mammal" , "Aquatic mammal" , "Maybe humpback" .)