memorial vs mnemonic

memorial

adj
  • Contained in the memory. 

  • Serving as a remembrance of someone or something; commemorative. 

noun
  • Something, such as a monument, by which someone or something is remembered. 

  • A chronicle or memoir. 

  • A service of remembrance or commemoration. 

  • A statement of facts set out in the form of a petition to a person in authority, a court or tribunal, a government, etc. 

mnemonic

adj
  • Of or relating to memory. 

  • Especially of a series of ideas, letters, words, etc.: intended to help in remembering. 

  • Of or relating to mnemonics (“the study of techniques for remembering anything more easily”). 

noun
  • Something (especially a series of ideas, letters, words, etc.) used to help in remembering a thing; a memory aid. 

  • The human-readable, textual form of an assembly language instruction, not including operands. 

How often have the words memorial and mnemonic occurred in a corpus of books? (source: Google Ngram Viewer )