1. happy go lucky
He was a very happy go lucky baby.
2. carefree easygoing
英語 "という言葉beztroski niefrasobliwy"(carefree easygoing)集合で発生します。
unit 9 page1533. blithe
She shows a blithe disregard for danger.
4. laid back
laid back
He's about to lose everything and just look at him, he's so laid back.