hairy arm noun1 •(slang) A purposeful flaw or obvious mistake introduced, usually to a graphic design, in order to bait or divert the attention of a boss or client who might otherwise focus on harder-to-fix or less trivial mistakes."You should always put a hairy arm into every project you work on, to give the client something to change. Of course, you've got to make the arm dumb enough." — 2000 formshairy arms
