lowering vs offloading

lowering

noun
  • The act of something being lowered. 

adj
  • Dark and menacing. 

  • Lurking, skulking, menacing. 

  • That lowers or frowns. 

offloading

noun
  • The act by which something is offloaded. 

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