The story
A meaningless word coined by the American comic strip writer Mort Walker (1923–2018) in a humorous article entitled “Let’s Get Down to Grawlixes” published in The Cartoonist (1964), possibly influenced by growl.
First known use, by meaning
- from mid 1960s An image resembling an illegible scribble used for this purpose.
Etymology from Wiktionary, CC BY-SA 4.0.