noun
feeling great; refreshed
Describes a state of feeling physically and mentally refreshed, often after exercise, a bath, or a good night's sleep.
朝のジョギングで汗を流したら、気分爽快になった。
After working up a sweat on my morning jog, I felt great.
温泉に入って気分爽快だ。
I feel refreshed after soaking in the hot spring.
Compound of 気分 (feeling, mood) and 爽快 (refreshing, exhilarating). The exact historical derivation is uncertain, but the combination directly conveys a state of refreshed feeling.