A provision is a store or supply of something, like food or clothing. This noun can also describe the planning you do for "when something happens."
We often use this word when we talk about outdoor activities like hiking or camping, or when we talk about outfitting an army in the field, but it basically means "supply." And since provision comes from the Latin word that means to "attend to," you can pretty much guess what the verb form of this word describes: the act of supplying someone else with provisions. In a legal or contractual sense, a provision is a stipulated condition or proviso.