expire

Expire is a verb meaning to come to an end of validity or to die; the noun expiration or expiry denotes the end point when something ceases to be in force or usable. The word derives from Latin exspirare, “to breathe out,” and has historically been used for both cessation of life and the ending of a term.

In everyday usage, expiration often refers to dates on foods and medicines. In food labeling, terms such as expiration date, use-by date, and best-by date are common. Use-by dates relate to safety and are typically more urgent; best-before dates relate to quality rather than safety. Many items can lose quality or potency after these dates, and some products may become unsafe to consume past them.

Legal, contractual, and regulatory contexts also employ expiration. A contract, license, or permit may expire at the end of a stated term, ending the arrangement unless renewed. Offers, rights, or warranties can expire if not acted upon. Intellectual property protections such as patents expire after their statutory term, unless extended by law.

In finance and technology, expiration has specific meanings as well. An option contract expires on its expiration date, ending its right to exercise. Digital security practices rely on token or session expiration to limit access, and certificates and licenses have explicit expiration dates.

In formal language, expire can also mean to die. The term remains a neutral, context-dependent way to describe the termination of validity, usefulness, or life. Practical management of expiration involves monitoring dates, proper storage, and timely disposal of expired items.