adobe vs building block

adobe

noun
  • The earth from which such bricks are made. 

  • An unburnt brick dried in the sun. 

  • A house made of adobe brick. 

building block

noun
  • A component that is part of a larger construction, such as a brick or a stone. 

  • A block made of wood or plastic that is used as a children's toy and can be stacked or joined to form a larger structure. 

  • A component that is part of a larger system. 

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