building block vs rubber stamp

building block

noun
  • 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. 

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

rubber stamp

noun
  • A piece of rubber or similar material with a design or text carved or molded for the purpose of transferring ink or dye to imprint that design on another object. 

  • A person or organisation that approves, routinely or as a formality, matters decided by some other person or organisation. 

adj
  • Of a person, organisation, or process, making decisions or approving matters routinely or without real power. 

verb
  • To process, approve or decide matters routinely rather than through careful consideration. 

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