The Collaborative International Dictionary of English v.0.48:

Depression \De*pres"sion\, n. [L. depressio: cf. F.
   d['e]pression.]
   1. The act of depressing.
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   2. The state of being depressed; a sinking.
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   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.
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   4. Humiliation; abasement, as of pride.
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   5. Dejection; despondency; lowness.
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            In a great depression of spirit.      --Baker.
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   6. Diminution, as of trade, etc.; inactivity; dullness.
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   7. (Astron.) The angular distance of a celestial object below
      the horizon.
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   8. (Math.) The operation of reducing to a lower degree; --
      said of equations.
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   9. (Surg.) A method of operating for cataract; couching. See
      Couch, v. t., 8.
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   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.
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