Scribble aimlessly (6)
I believe the answer is:
doodle
'scribble aimlessly' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for doodle that I've seen before include "Scribbled drawing" , "Aimless scribble" , "Aimless drawing" , "Scribble aimlessly or absent-mindedly" , "Scrawl aimlessly or absent-mindedly" .)