The word "lube" is a slang term short for "lubricant." It refers to a substance, usually a liquid or gel, that is used to reduce friction between surfaces in motion, making it easier for those surfaces to move smoothly against each other. Lubricants are commonly used in mechanical contexts, like in engines or machinery, and in personal contexts, such as in sexual activity to enhance comfort and pleasure.
The term "lube" is derived from the word "lubricant," which comes from the Latin word "lubricus," meaning "slippery" or "oily." The abbreviation "lube" became popular in informal contexts.