Word Origin & History
"scrawl aimlessly," 1935, from dial. doodle, dudle "fritter away time, trifle." It was a noun meaning "simple fellow" from 1620s.
LONGFELLOW: That's a name we made up back home for people who make foolish designs on paper when they're thinking. It's called doodling. Almost everybody's a doodler. Did you ever see a scratch pad in a telephone booth? People draw the most idiotic pictures when they're thinking. Dr. Von Holler, here, could probably think up a long name for it, because he doodles all the time. ["Mr. Deeds Goes to Town," screenplay by Robert Riskin, 1936; based on "Opera Hat," serialized in "American Magazine" beginning May 1935, by Clarence Aldington Kelland]
Related: Doodling. Doodle-bug "type of beetle or larvae" is c.1866, Southern U.S. dialect; the same word was applied 1944 in R.A.F. slang to German V-model flying bombs