This is the 9132nd most frequent Japanese word.
無為
"無為" (mui) means "inaction" or "non-doing," often implying effortless action or natural state.
In this sentence, '無為' is used as an adjective to describe a state of inactivity or unproductiveness.
彼は無為な日々を過ごしている。
He is spending idle days.
Here, '無為' functions as an adverbial noun, implying spending time in an unengaged or aimless manner.
無為に時間を過ごしてはいけない。
You shouldn't spend time idly.
In this context, '無為' refers to a philosophical concept of effortless action or naturalness, often associated with Taoist thought.