1.
selflessness; absorbed state; self-forgetfulness
Being so absorbed in an activity or emotion that one forgets oneself. Most commonly seen in the set phrase 無我夢中.
2.
no-self (Buddhist concept of anātman)
The Buddhist doctrine that there is no permanent, independent self — one of the three marks of existence. Used in Buddhist and philosophical contexts.
Composed of 無 (without) + 我 (self, ego). In daily Japanese the everyday sense (self-forgetful absorption) is far more common than the Buddhist doctrinal sense.