I'm to intercede without delay (9)

I believe the answer is:

immediate

'without delay' is the definition.
(I've seen this before)

'i'm to intercede' is the wordplay.
'to intercede' becomes 'mediate' ('mediate' can be a synonym of 'intercede').
'im'+'mediate'='IMMEDIATE'

(Other definitions for immediate that I've seen before include "Instantaneous" , "Involving no delay" , "Occurring without delay" , "Prompt,straightaway" , "Present" .)

I've seen this clue in The Guardian, The Telegraph, The Times and The Sun.

Want a hint initially instead of a full solution? Install my app