lessen vs pyramid

lessen

verb
  • To make less; to diminish; to reduce. 

  • To become less. 

conj
  • unless. 

pyramid

noun
  • A medullary pyramid, the medial-most bumps on the ventral side of the medulla oblongata 

  • A pyramid scheme. 

  • The triangular layout of cards in the game of Pyramid. 

  • An ancient massive construction with a square or rectangular base and four triangular sides meeting in an apex, such as those built as tombs in Egypt or as bases for temples in Mesoamerica. 

  • An approximately triangular headline consisting of several centered lines of text of increasing length. 

  • A solid with triangular lateral faces and a polygonal (often square or rectangular) base. 

  • A construction in the shape of a pyramid, usually with a square or rectangular base. 

verb
  • To employ, or take part in, a pyramid scheme. 

  • To combine (a series of genes) into a single genotype. 

  • To engage in pyramid trading. 

  • To build up or be arranged in the form of a pyramid. 

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