doodle
Concise Oxford English Dictionary © 2008 Oxford University Press:
doodle/ˈduːdl/
▶verb scribble absent-mindedly. ▶noun a drawing made absent-mindedly.
– derivatives
doodler noun,
doodling noun.
doodler noun,
doodling noun.
– origin C17 (orig. as n. denoting a fool): from Low Ger. dudeltopf, dudeldopp ‘simpleton’.
'doodle' also found in these Oxford entries:

