Mottainai (もったいない, [mottainai]) is a Japanese term conveying a sense of regret concerning waste. The expression "Mottainai!" can be uttered alone as an exclamation when something useful, such as food or time, is wasted, meaning roughly "what a waste!" or "Don't waste." In addition to its primary sense of "wastefulness", the word is also used to mean "impious; irreverent" or "more than one deserves".