Mark gets married during insensibility (5)
I believe the answer is:
comma
'mark' is the definition.
(punctuation mark)
'married during insensibility' is the wordplay.
'married' becomes 'm'.
'during' is an insertion indicator.
'insensibility' becomes 'coma' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'm' inserted inside 'coma' is 'COMMA'.
'gets' is the link.
Can you help me to learn more?
(Other definitions for comma that I've seen before include "List-item separator" , "Kind of butterfly" , "Common punctuation park" , "shortest interval" , ", (stet)" .)