ablutions vs powder room

ablutions

noun
  • A building that houses bathing and toilet facilities on a military base. 

  • The location or building where the showers and basins are located. 

powder room

noun
  • A room used to store gunpowder, particularly (historical) on a ship equipped with cannon. 

  • Synonym of ladies' room: a lavatory intended for use by women. 

  • A room used to powder hair and wigs. 

  • Synonym of half bath: a small room with a toilet and sink but no bathtub or shower. 

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