Come close to marrying two farm animals in the proverb (7)
I believe the answer is:
epigram
'the proverb' is the definition.
(thesaurus)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for epigram that I've seen before include "Sally perhaps" , "Concise witty saying" , "Concise witty remark" , "A clever witty saying" , "Bon mot" .)