See the temptation about sordid gain (5)
I believe the answer is:
lucre
'sordid gain' is the definition.
(I've seen this before)
'see the temptation about' is the wordplay.
'see' becomes 'c' (the word for the letter, according to Chambers).
'the temptation' becomes 'lure' (lure is a kind of temptation).
'about' means one lot of letters goes inside another.
'c' put into 'lure' is 'LUCRE'.
(Other definitions for lucre that I've seen before include "tin" , "Wealth - cruel (anag)" , "Money or wealth" , "Ill-gotten riches" , "ill-gotten gains" .)