“mo us” is likely “mousse”. It is pronounced as /muːs/. The “ou” in “mousse” makes a long “u” sound as in “moon”. It is a French word often used in English to refer to a light and airy dessert or a styling product for hair. For example, “chocolate mousse” is a popular dessert. When used as a hair product, it can give volume and hold. Remember to pronounce it with a soft “s” sound at the end.