The first of a five-tiered method of quanitifying an amount of liquid beverage (often alcoholic) consumed without removing the vessel from the lips. The tiers are sip, swip, swig, swug and chug. This is the smallest of the tiers and connotes a very small amount of beverage actually consumed. Often used falesly in order to induce another person to allow you to share their beverage.
Short for "Sand In Pussy"
When a girl gets aggitated, and you think it is PMSing, she really has sand in her pussy, mainly on the clit.
Dude, i was getting reaqdy to fuck Regina, and she had the worst attitude, ever, so i asked what the fuck was going on, and she later told me she had the, SIP. So I had to clean her out.