Source : Webster's Revised Unabridged Dictionary (1913)

Depression \De*pres"sion\, n. [L. depressio: cf. F.
   d['e]pression.]
   1. The act of depressing.

   2. The state of being depressed; a sinking.

   3. A falling in of the surface; a sinking below its true
      place; a cavity or hollow; as, roughness consists in
      little protuberances and depressions.

   4. Humiliation; abasement, as of pride.

   5. Dejection; despondency; lowness.

            In a great depression of spirit.      --Baker.

   6. Diminution, as of trade, etc.; inactivity; dullness.

   7. (Astron.) The angular distance of a celestial object below
      the horizon.

   8. (Math.) The operation of reducing to a lower degree; --
      said of equations.

   9. (Surg.) A method of operating for cataract; couching. See
      {Couch}, v. t., 8.

   {Angle of depression} (Geod.), one which a descending line
      makes with a horizontal plane.

   {Depression of the dewpoint} (Meteor.), the number of degrees
      that the dew-point is lower than the actual temperature of
      the atmosphere.

   {Depression of the pole}, its apparent sinking, as the
      spectator goes toward the equator.

   {Depression of the visible horizon}. (Astron.) Same as {Dip
      of the horizon}, under {Dip}.

   Syn: Abasement; reduction; sinking; fall; humiliation;
        dejection; melancholy.