Spread of, say, strike rising (5)
I believe the answer is:
marge
'spread' is the definition.
(marge is a kind of spread)
'say strike rising' is the wordplay.
'say' becomes 'eg'.
'strike' becomes 'ram' (I've seen this before**).
'rising' is a reversal indicator (going up in a down clue).
'eg'+'ram'='egram'
'egram' reversed gives 'MARGE'.
'of' acts as a link.
(Other definitions for marge that I've seen before include "Butter-like spread" , "limit" , "Homer Simpson's wife; a spread (abbr.)" , "Homer's wife" , "edge, poetically" .)