happy-go-lucky　

adj.逍遥自在的lucky意思；无忧无虑的

例句

用作形容词 (adj.)

That girl is the most happy- go- lucky person I know.

那个女孩是我所认识的人当中最无忧无虑的人。

He began to talk and laugh, in happy, thoughtless, boyish fashion, as we walked along, and made himself old friends with me at once.

我跟他往前走着，他就谈笑起来，高高兴兴的，无忧无虑的，非常孩子气，还真是跟我一见如故。