flagging vs reflux

flagging

noun
  • The process by which something flags or tires. 

  • A pavement or sidewalk of flagstones; flagstones, collectively. 

  • The skewing or bending of the upper part of a television picture due to imperfect synchronization of the video signal. 

  • Use of a handkerchief code or analogous display to signal sexual interests. 

adj
  • Becoming tired or less dynamic; declining in strength; dwindling. 

reflux

noun
  • The backwards flow of any fluid. 

  • A technique, using a reflux condenser, allowing one to boil the contents of a vessel over an extended period. 

  • The leaking of stomach acid up into the oesophagus. 

verb
  • To boil a liquid in a vessel having a reflux condenser 

  • To flow back or return. 

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