When speaking, cover up blame (3)
I believe the answer is:
rap
'blame' is the definition.
(I know that blame can be written as rap)
'when speaking cover up' is the wordplay.
'when speaking' shows a homophone (sound like).
'cover up' becomes 'wrap' (I've seen this before).
'wrap' is a homophone of 'RAP'.
(Other definitions for rap that I've seen before include "Knock - punishment - monologue to music" , "Knock sharply" , "Knock for par" , "Sharp knock; rebuke" , "Music; charge; strike" .)