Synonyms: devil-may-care, slaphappy, happy-go-lucky, harum-scarum, carefree, freewheeling
Definition: cheerfully irresponsible
Usage: carefree with his money; freewheeling urban youths; had a harum-scarum youth
Similar words: irresponsible
Definition: showing lack of care for consequences
Usage: behaved like an irresponsible idiot; hasty and irresponsible action