sagging vs swaying

sagging

noun
  • The act of something that sags. 

  • A manner of wearing pants or shorts below the waist, revealing some or all of the underwear. 

adj
  • Worn low on the waist, or wearing pants or shorts low on the waist. 

  • Hanging down loosely. 

swaying

noun
  • The motion of something that sways. 

  • An injury caused to a horse's back by violent strains or overloading. 

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