I, for one, run away with amoral men (5,7)
I believe the answer is:
roman numeral
'i for one' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'run away with amoral men' is the wordplay.
'away with' indicates anagramming the letters (letters move away from their original places).
'amoral'+'men'='amoralmen'
'run' with its letters mixed up with 'amoralmen' gives 'ROMAN NUMERAL'.
Can you help me to learn more?
(Other definitions for roman numeral that I've seen before include "I, perhaps" , "I say" , "Such as V, X or L" , "Eg, X or V or M" , "I for one!" .)