doo·dle 
(ddl)
(ddl)v. doo·dled, doo·dling, doo·dles
v.intr.
1. To draw or sketch aimlessly, especially when preoccupied.
2. To kill time; dawdle.
v.tr.
To draw (figures) while preoccupied.
n.
A figure or design drawn or written absent-mindedly.
[English dialectal, to fritter away time, perhaps from doodle, fool; see DOODLEBUG.]
doodler n.