Slang for a woman's vulva, specifically the labia majora, which in a non-aroused state resemble lips pressed together but with a distinctive, tight seam down the middle.
Mark: did you see Sandra in the nude?
Dave: yeah, she's got a nice rack and a cute little splitsie
Mark: what a doll!
An agreement arranged prior to eating in which two meals that are capable of being split in half (eg. a tuna sandwich and a low carb chicken wrap) are split evenly among the two diners, resulting in each of them having half of the other's meal.
Changing relationship status in facebook and removing the notification from the time-line in a split second so that your friends won't ask you why went from married to single.
"Joyce is no longer in a relationship"...Now click "Remove" on the notification in a split second before anyone reads about the change! That is a splitsecond split.