1. To slip across the edge of something and fall down. He lost his footing and slid over the side of the roof, breaking his ankle in the fall. The car lost control on the ice and slid over the cliff.

2. To cause someone or something to move closer (to someone or something else) while maintaining smooth, continual contact with some surface. In this usage, a noun or pronoun can be used between "slide" and "over." Slide over the contract so I can have a look at the fine print. Slide the patient over on the trolley so we can examine him in the light.

3. To move one's position so as to make more space available for another person. Tom, would you slide over and make some room for Jack at the table? I wish this car ahead of us would just shove over a tiny bit so we could pass him!