effloresce \ef`floresce"\, v. i. imp.  p. p. effloresced;
   p. pr.  vb. n. efflorescing. l. efflorescere to bloom,
   blossom; ex + florescere to begin to blossom, incho., fr.
   florere to blossom, fr. flos a flower. see flower.
   1. to blossom forth. --carlyle.
      1913 webster

   2. chem. to change on the surface, or throughout, to a
      whitish, mealy, or crystalline powder, from a gradual
      decomposition, esp. from the loss of water, on simple
      exposure to the air; as, glauber's salts, and many others,
      effloresce.
      1913 webster

   3. to become covered with a whitish crust or light
      crystallization, from a slow chemical change between some
      of the ingredients of the matter covered and an acid
      proceeding commonly from an external source; as, the walls
      of limestone caverns sometimes effloresce with nitrate of
      calcium in consequence of the action of nitric acid formed
      in the atmosphere.
      1913 webster
see also:
effloresced efflorescing flower