For a Conservative to wear running gear isnt novel (5,5)
I believe the answer is:
short story
'novel' is the definition.
(thesaurus)
'for a conservative to wear running gear isnt' is the wordplay.
I cannot quite see how this works, but
'for' could be 'to' (eg both can mean 'in the opinion of') and 'to' is located in the answer.
'wear' could be 'shorts' (shorts is a kind of wear) and 'shorts' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for short story that I've seen before include "That's hardly novel" , "tale" , "not much material to take in" , "Novella" , "little romance, say?" .)