diligently; faithfully; without fail
Used to describe doing something carefully and consistently, without neglecting duties or making careless mistakes. Often implies a sense of responsibility and thoroughness.
He handles his work diligently.
I keep a diary every day without fail.
Standard kanji-kana spelling.
Alternate spelling using the kanji 無 for なく.
Adverbial form of the negative of the verb 怠る (おこたる, 'to neglect'), literally meaning 'without neglecting'.