also: あっぱらぱあ
noun, na-adjective
carefree; easygoing; happy-go-lucky
Colloquial term describing a person who is relaxed, unworried, and not easily bothered. Often used in a light, slightly humorous way.
彼はいつもアッパラパーで、何があっても気にしない。
He's always carefree and doesn't worry no matter what happens.
あのアッパラパーな性格が羨ましいよ。
I envy that easygoing personality.