'Happy-go-lucky' definitions:

Definition of 'happy-go-lucky'

adjective

Cheerfully irresponsible; "carefree with his money"; "freewheeling urban youths"; "had a harum-scarum youth" [syn: carefree, devil-may-care, freewheeling, happy-go-lucky, harum-scarum, slaphappy]

From: GCIDE

Happy \Hap"py\ (h[a^]p"p[y^]), a. [Compar. Happier (-p[i^]*[~e]r); superl. Happiest.] [From Hap chance.]
1. Favored by hap, luck, or fortune; lucky; fortunate; successful; prosperous; satisfying desire; as, a happy expedient; a happy effort; a happy venture; a happy omen. [1913 Webster]
Chymists have been more happy in finding experiments than the causes of them. --Boyle. [1913 Webster]
2. Experiencing the effect of favorable fortune; having the feeling arising from the consciousness of well-being or of enjoyment; enjoying good of any kind, as peace, tranquillity, comfort; contented; joyous; as, happy hours, happy thoughts. [1913 Webster]
Happy is that people, whose God is the Lord. --Ps. cxliv. 15. [1913 Webster]
The learned is happy Nature to explore, The fool is happy that he knows no more. --Pope. [1913 Webster]
3. Dexterous; ready; apt; felicitous. [1913 Webster]
One gentleman is happy at a reply, another excels in a in a rejoinder. --Swift. [1913 Webster]
Happy family, a collection of animals of different and hostile propensities living peaceably together in one cage. Used ironically of conventional alliances of persons who are in fact mutually repugnant.
Happy-go-lucky, trusting to hap or luck; improvident; easy-going. "Happy-go-lucky carelessness." --W. Black. [1913 Webster]