Moralistic type’s play on words taking in girl (7)
I believe the answer is:
puritan
'moralistic type's' is the definition.
(I've seen this before)
'play on words taking in girl' is the wordplay.
'play on words' becomes 'pun' (synonyms).
'taking in' is an insertion indicator.
'girl' becomes 'rita' (woman's name).
'pun' enclosing 'rita' is 'PURITAN'.
(Other definitions for puritan that I've seen before include "Over-strict moralist" , "Person of extreme moral strictness" , "Person of extremely strict morals" , "One forgoing pleasure" , "Prude" .)