I'm holding a number said to be corrupt (7)
I believe the answer is:
immoral
'be corrupt' is the definition.
(similar in meaning)
'i'm holding a number said' is the wordplay.
'holding' is a charade indicator (letters next to each other).
'a number' becomes 'm' (M is an example).
'said' becomes 'oral' (both can mean spoken).
'im'+'m'+'oral'='IMMORAL'
'to' acts as a link.
(Other definitions for immoral that I've seen before include "Not conforming to accepted rules of conduct, particularly in sexual matters" , "Wicked" , "Licentious - dissolute" , "bad!" , "Lacking a sense of right and wrong" .)