Thus get wife an animal (3)
I believe the answer is:
sow
'an animal' is the definition.
(female pig)
'thus get wife' is the wordplay.
'thus' becomes 'so' (synonyms).
'get' says to put letters next to each other.
'wife' becomes 'w' (abbreviation).
'so'+'w'='SOW'
(Other definitions for sow that I've seen before include "One who takes care of litter" , "Female badger" , "Plant seeds for the pig" , "Prepare farmland" , "Broadcast" .)