Brawn or steak patty (8)
I believe the answer is:
beefcake
'brawn' is the definition.
Both the answer and definition are singular nouns.
Perhaps there's a link between them I don't understand?
'steak patty' is the wordplay.
'steak' becomes 'beef' (I can't explain this - if you can you should believe this answer much more).
'patty' becomes 'cake' (synonyms).
'beef'+'cake'='BEEFCAKE'
'or' acts as a link.
Can you help me to learn more?
(Other definitions for beefcake that I've seen before include "Men displaying muscles" , "Certain photos" , "Photo of a muscular man with not much on" , "Displayed male muscles" , "Attractive muscular men" .)