By the previous wife, do right (5)
I believe the answer is:
exact
'right' is the definition.
(similar in meaning)
'by the previous wife do' is the wordplay.
'by' says to put letters next to each other.
'the previous' becomes 'ex' (prefix meaning former or onetime).
'wife do' becomes 'act' (I can't justify this - if you can you should give a lot more credence to this answer).
'ex' put next to 'act' is 'EXACT'.
Can you help me to learn more?
(Other definitions for exact that I've seen before include "without rounding" , "Demand, extort" , "Precise, accurate" , "As a right, demand" , "Precise - demand" .)