interjection
An exclamation of surprise, dismay, or mild shock. Abbreviation of 南無三宝 (なむさんぼう), a Buddhist invocation. Somewhat old-fashioned or dramatic; in modern casual speech, あっ or やばい are more common.
See also: 南無三宝
南無三、財布を忘れた！
Oh no, I forgot my wallet!
南無三、また遅刻だ。
Good heavens, I'm late again.
Abbreviation of 南無三宝 (なむさんぼう), a Buddhist invocation meaning 'homage to the Three Treasures (Buddha, Dharma, Sangha)'. The exact historical path from religious phrase to secular exclamation is uncertain.