moss [OE] The earliest recorded use of moss in English was ‘bog, swamp’, a sense still found in northern England and Scotland, but this may just be the chance of what has survived, for the plant sense is found not much later, and in the other languages that share its Germanic root the word is found in both senses. The French form of ‘moss’ was mousse [E19th], used of both moss and foam, and first recorded in English of the bubbles on the surface of champagne, before being used of the type of food some twenty years later. See also litmus.