compartment vs undercroft

compartment

noun
  • A room, or section, or chamber 

  • Part of a protein that serves a specific function. 

  • A mound (often of grass) beneath the shield in a coat of arms on which the supporters stand. 

  • One of the parts into which an area is subdivided. 

  • A region in the body, delimited by a biological membrane. 

verb
  • To arrange in separate compartments. 

undercroft

noun
  • A cellar or vaulted storage room. 

  • A ground-level car park that occupies the base of a building. 

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