com·mem·o·rate / kəˈmeməˌrāt/ • v. [tr.] recall and show respect for (someone or something) in a ceremony: a ceremony to commemorate the war dead. ∎  serve as a memorial to: a stone commemorating a boy who died at sea. ∎  mark (a significant event). ∎  (often be commemorated) celebrate (an event, a person, or a situation) by doing or building something: it was a night commemorated in a song.DERIVATIVES: com·mem·o·ra·tor / -ˌrātər/ n.

commemorate XVI. f. pp. stem of L. commemorāre, f. COM- (intensive) + memorāre relate, f. memor mindful (see MEMORY).
So commemoration XIV. — (O)F. or L.