Spit refers to saliva or to the act of ejecting salava from one's mouth.
Spit, also known as saliva, lubricates the mouth and food as we chew it. Spit also has a number of erotic uses. By spitting - the act of ejecting saliva - onto one's hand, one can use spit as a lubricant for either masturbation or intercourse. Spit can be used to lubricate the penis, anus or vagina of sexual partners. Spitting on someone is a way of humiliating them or showing them contempt, so spit is also used in BDSM and humiliation sessions.