What is the meaning of commemorating?

verb

• Mark by some ceremony or observation.
  • usage: "The citizens mark the anniversary of the revolution with a march and a parade"
  • synonyms: commemorate, mark
• Call to remembrance; keep alive the memory of someone or something, as in a ceremony.
  • usage: "We remembered the 50th anniversary of the liberation of Auschwitz"; "Remember the dead of the First World War"
  • synonyms: commemorate, remember
• Be or provide a memorial to a person or an event.
  • usage: "This sculpture commemorates the victims of the concentration camps"; "We memorialized the Dead"
  • synonyms: commemorate, memorialize, memorialise, immortalize, immortalise, record

adjective

• Intended as a commemoration.
  • usage: "a commemorative plaque"
  • synonyms: commemorative