\HAIR-uh m-SKAIR-uh m, HAR-uh m-SKAR-uh m\
adjective
1. reckless; rash; irresponsible: He had a harum-scarum youth.
2. disorganized; uncontrolled.
Quotes
… he warn’t bad, so to say–only mischeevous. Only just giddy and harum-scarum, you know. He warn’t any more responsible than a colt.
— Mark Twain, The Adventures of Tom Sawyer, 1876