"Expire" refers to the process of something coming to an end or reaching its limit. This term is commonly used in relation to food, medications, or documents, indicating that they are no longer safe or valid to use after a certain date. For example, a milk carton may have an expiration date printed on it, signifying when it should no longer be consumed. In a broader context, "expire" can also apply to contracts or agreements, which become void after a specified period. When a credit card expires, it means that it can no longer be used for transactions, and a new card must be issued to continue making purchases.