[1] : The Collaborative International Dictionary of English v.0.48

vapor \va"por\, n. oe. vapour, of. vapour, vapor, vapeur, f.
   vapeur, l. vapor; probably for cvapor, and akin to gr. ?
   smoke, ? to breathe forth, lith. kvepti to breathe, smell,
   russ. kopote fine soot. cf. vapid. written also
   vapour.
   1913 webster
   1. physics any substance in the gaseous, or aeriform,
      state, the condition of which is ordinarily that of a
      liquid or solid.
      1913 webster

   note: the term vapor is sometimes used in a more extended
         sense, as identical with gas; and the difference
         between the two is not so much one of kind as of
         degree, the latter being applied to all permanently
         elastic fluids except atmospheric air, the former to
         those elastic fluids which lose that condition at
         ordinary temperatures. the atmosphere contains more or
         less vapor of water, a portion of which, on a reduction
         of temperature, becomes condensed into liquid water in
         the form of rain or dew. the vapor of water produced by
         boiling, especially in its economic relations, is
         called steam.
         1913 webster

               vapor is any substance in the gaseous condition
               at the maximum of density consistent with that
               condition. this is the strict and proper meaning
               of the word vapor.                 --nichol.
         1913 webster

   2. in a loose and popular sense, any visible diffused
      substance floating in the atmosphere and impairing its
      transparency, as smoke, fog, etc.
      1913 webster

            the vapour which that fro the earth glood glided.
                                                  --chaucer.
      1913 webster

            fire and hail; snow and vapors; stormy wind
            fulfilling his word.                  --ps. cxlviii.
                                                  8.
      1913 webster

   3. wind; flatulence. obs. --bacon.
      1913 webster

   4. something unsubstantial, fleeting, or transitory; unreal
      fancy; vain imagination; idle talk; boasting.
      1913 webster

            for what is your life? it is even a vapor, that
            appeareth for a little time, and then vanisheth
            away.                                 --james iv.
                                                  14.
      1913 webster

   5. pl. an old name for hypochondria, or melancholy; the
      blues. "a fit of vapors." --pope.
      1913 webster

   6. pharm. a medicinal agent designed for administration in
      the form of inhaled vapor. --brit. pharm.
      1913 webster

   vapor bath.
      a a bath in vapor; the application of vapor to the body,
          or part of it, in a close place; also, the place
          itself.
      b chem. a small metallic drying oven, usually of
          copper, for drying and heating filter papers,
          precipitates, etc.; -- called also air bath. a
          modified form is provided with a jacket in the outside
          partition for holding water, or other volatile liquid,
          by which the temperature may be limited exactly to the
          required degree.

   vapor burner, a burner for burning a vaporized hydrocarbon.
      

   vapor density chem., the relative weight of gases and
      vapors as compared with some specific standard, usually
      hydrogen, but sometimes air. the vapor density of gases
      and vaporizable substances as compared with hydrogen, when
      multiplied by two, or when compared with air and
      multiplied by 28.8, gives the molecular weight.

   vapor engine, an engine worked by the expansive force of a
      vapor, esp. a vapor other than steam.
      1913 webster
see also:
vapid vapour vapor bath air bath vapor burner vapor density 
vapor engine 

Burner >> B Words
Burner, definition of term: Burner
burner_pag1.html

Vapor >> V Words
Vapor, definition of term: Vapor
vapor_pag1.html

Vapor Pressure >> V Words
Vapor Pressure, definition of term: Vapor Pressure
vapor+pressure_pag1.html

Water Vapor >> W Words
Water Vapor, definition of term: Water Vapor
water+vapor_pag1.html

Bunsen Burner >> B Words
Bunsen Burner, definition of term: Bunsen Burner
bunsen+burner_pag1.html