University dons this writer had to mock (7)
I believe the answer is:
imitate
'mock' is the definition.
(thesaurus)
'university dons this writer had' is the wordplay.
'university' becomes 'mit' (I've seen this in other clues).
'dons' means one lot of letters goes inside another (don means to wear or put on).
'this writer' becomes 'i' (the person who is writing these clues).
'had' becomes 'ate' (e.g. I had an ice cream).
'i'+'ate'='iate'
'mit' put within 'iate' is 'IMITATE'.
'to' acts as a link.
(Other definitions for imitate that I've seen before include "Copy someone" , "Copy, simulate" , "Take as a model" , "Copy or mimic" , "I tame it to copy it" .)