Agitate Arab leader by the sound of it (5)
I believe the answer is:
shake
'agitate' is the definition.
(I know that agitate can be written as shake)
'arab leader by the sound of it' is the wordplay.
'arab leader' becomes 'sheik' (I've seen this before).
'by the sound of it' indicates a 'sounds like' (homophone) clue.
'sheik' is a homophone of 'SHAKE'.
(Other definitions for shake that I've seen before include "Vibrate; drink" , "moment" , "rock" , "Upset" , "Quiver" .)