Forfeiture restraint is a legal provision that limits the transfer or ownership of property by imposing conditions that, if violated, can result in the automatic loss of the property. This type of restraint is often used in the context of estates and future interests to ensure that property remains within a specified group or is used in accordance with the grantor's intent. It serves to prevent disallowed uses or transfers, thereby protecting the interests of the original grantor and maintaining control over how the property is utilized.