Word To Use Today: mottanai.

Mottainai (you say the ai bits like the word I) is a word of Japanese origin. It's to do with regret at wasting things, whether physical objects such as food, or perhaps time, or even thoughts.

Mottainai! as an exclamation means That's a terrible waste! 

In Japan, mottainai is part of a movement that encourages the mending of possessions so they can be used as long as possible, and now the word has moved out of Japan and has been taken up by environmental campaigners all over the world. It's even been used by anti-war campaigners, working on the principle that if we don't waste things there'll be enough to go round and we won't need to fight for what's left. 

Somehow I doubt war is quite as simple as that: but it can only be a help.

Word To Use Today: mottainai. This word has been around since the 1200s, and started off being to do with the sense of gratitude and unworthiness when receiving benefits from a superior. 

At root, it's a Buddhist idea. Mottai is to do with the sacredness and worth of a material object, and nai means lack of.