efflorescence vs pompon

efflorescence

noun
  • The production of flowers. 

  • Rapid flowering of a culture or civilisation etc. 

  • The formation of a powdery surface on crystals, as a hydrate is converted to anhydrous form by losing loosely bound water of crystallization to the atmosphere. 

  • A redness, rash, or eruption on the skin. 

  • An encrustation of soluble salts, deposited on rock or soil by evaporation; often found in arid or geothermal environments. 

  • An encrustation of soluble salts, commonly white, deposited on the surface of stone, brick, plaster, or mortar; usually caused by free alkalies leached from mortar or adjacent concrete as moisture moves through it. 

pompon

noun
  • A hardy garden chrysanthemum with button-like flower heads. 

  • A bundle of yarn, string, ribbon, etc. tied in the middle and left loose at the ends, so as to form a puff or ball, as for decoration or a showy prop for cheerleading. 

  • Any of several dwarf varieties of the Provence rose. 

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