1610s, from commemorate + -ive. As a noun meaning "means of commemoration" it is recorded from 1630s; as short for commemorative postage stamp from 1916.

something done to honor an historical event or person.

Use for items produced, issued, or worn to commemorate a person, event, or occasion. For structures erected to preserve the memory of persons or events, use "memorials."

A stamp printed in a limited quantity and available for purchase for a limited time. The design may note an anniversary associated with an individual, an historic event, or a national landmark. See al [..]

(n) an object (such as a coin or postage stamp) made to mark an event or honor a person(adj) intended as a commemoration

In firearms parlance, a gun that was manufactured in "limited" numbers (often into the thousands), marked, stamped or fitted with extra bells and whistles in such a way as to evoke r [..]

  A gift to honor or in memory of a special individual or loved one that can be directed to any area of the university. Gifts can also commemorate a special occasion, birthday or graduation.