The term seize is to capture or take possession of, with legal authority, property or a person.
For example, one of the greatest freedoms protected by the US Constitution is the right to privacy. The Fourth Amendment protects a person’s privacy by limiting law enforcement agents’ power of search and seizure.
Generally, this means that they can’t search you or your home or seize your personal property without having a good reason for doing so. And, unless some specific exception applies, they have to have a warrant before they make a search or seizure.