The term of a patent: the amount of time during which a patent can be enforced.
The term of a patent is the time period during which it can be enforced. After a patent expires, the invention is no longer protected by this patent.
The exact term of a patent depends on the jurisdiction and can be subject to special cases. In most countries including the United States, the term of a utility patent is now 20 years from the filing date in most cases. For US patents filed before 1995, the term is up to 17 years after the application date. Design patents have a shorter term (14 years from issue in the US).
A patent can expire before its maximum term if the maintenance fees are not paid.