Lubricant. Lubricant—lube for short—is a liquid or jelly people can put on a penis or a sex toy to make it slide more easily during sex, and to reduce friction. This helps for vaginal or anal penetration, and it’s essential for anal sex. A lot of people use it to make masturbation easier too, especially folks with a circumcised penis.

Synonyms:
lube, lubes, lubricate, lubrication