Open English Wordnet
Nouns
(n)daredevil, madcap, hothead, swashbuckler, lunatic, harum-scaruma reckless impetuous irresponsible person
Adjectives
(s)carefree, devil-may-care, freewheeling, happy-go-lucky, harum-scarum, slaphappycheerfully irresponsible“carefree with his money”, “freewheeling urban youths”, “had a harum-scarum youth”
Adverbs
(r)harum-scarum, pell-mellin a wild or reckless manner“dashing harum-scarum all over the place”, “running pell-mell up the stairs”