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carefree; comfortable; at ease
easygoing; happy-go-lucky
休みの日は気楽に過ごす。
On days off, I spend time at ease.
一人暮らしは気楽でいいよ。
Living alone is carefree and nice.
気楽な気持ちで試験に臨んだほうがいい結果が出る。
You get better results if you approach the exam with a relaxed mindset.