I perhaps spread normal manure (5,7)
I believe the answer is:
roman numeral
'i' is the definition.
(I is the Roman numeral for one)
'spread normal manure' is the wordplay.
'spread' indicates an anagram.
'normal'+'manure'='normalmanure'
'normalmanure' anagrammed gives 'ROMAN NUMERAL'.
'perhaps' acts as a link.
(Other definitions for roman numeral that I've seen before include "I for one!" , "Such as V, X or L" , "I say" , "Eg, X or V or M" , "I, perhaps" .)