Source : Webster's Revised Unabridged Dictionary (1913)

Calm \Calm\ (k[aum]m), n. [OE. calme, F. calme, fr. It. or Sp.
   calma (cf. Pg. calma heat), prob. fr. LL. cauma heat, fr. Gr.
   kay^ma burning heat, fr. kai`ein to burn; either because
   during a great heat there is generally also a calm, or
   because the hot time of the day obliges us seek for shade and
   quiet; cf. {Caustic}]
   Freedom from motion, agitation, or disturbance; a cessation
   or absence of that which causes motion or disturbance, as of
   winds or waves; tranquility; stillness; quiet; serenity.

         The wind ceased, and there was a great calm. --Mark.
                                                  iv. 39.

         A calm before a storm is commonly a peace of a man's
         own making.                              --South.

Calm \Calm\, v. i. [imp. & p. p. {Calmed}; p. pr. & vb. n.
   {Calming}.] [Cf. F. calmer. See {Calm}, n.]
   1. To make calm; to render still or quiet, as elements; as,
      to calm the winds.

            To calm the tempest raised by Eolus.  --Dryden.

   2. To deliver from agitation or excitement; to still or
      soothe, as the mind or passions.

            Passions which seem somewhat calmed.  --Atterbury.

   Syn: To still; quiet; appease; allay; pacify; tranquilize;
        soothe; compose; assuage; check; restrain.

Calm \Calm\ (k[aum]m), a. [Compar. {Calmer} (-[~e]r); super.
   {Calmest} (-[e^]st)]
   1. Not stormy; without motion, as of winds or waves; still;
      quiet; serene; undisturbed. ``Calm was the day.''
      --Spenser.

            Now all is calm, and fresh, and still. --Bryant.

   2. Undisturbed by passion or emotion; not agitated or
      excited; tranquil; quiet in act or speech. ``Calm and
      sinless peace.'' --Milton. ``With calm attention.''
      --Pope.

            Such calm old age as conscience pure And
            self-commanding hearts ensure.        --Keble.

   Syn: Still; quiet; undisturbed; tranquil; peaceful; serene;
        composed; unruffled; sedate; collected; placid.

Source : WordNet®

calm
     n : steadiness of mind under stress; "he accepted their problems
         with composure and she with equanimity" [syn: {composure},
          {calmness}, {equanimity}] [ant: {discomposure}]

calm
     adj 1: not agitated; without losing self-possession; "spoke in a
            calm voice"; "remained calm throughout the uproar"
            [syn: {unagitated}]
     2: characterized by absence of emotional agitation; "calm
        acceptance of the inevitable"; "remained serene in the
        midst of turbulence"; "a serene expression on her face";
        "she became more tranquil"; "tranquil life in the country"
        [syn: {serene}, {tranquil}]
     3: (of weather) free from storm or wind; "calm seas" [ant: {stormy}]
     4: marked by freedom from agitation or excitement; "the rioters
        gradually became calm and slowly dispersed"

calm
     v 1: make calm or still; "quiet the dragons of worry and fear"
          [syn: {calm down}, {quiet}, {tranquilize}, {tranquillize},
           {tranquillise}, {quieten}, {lull}, {still}] [ant: {agitate}]
     2: make steady; "steady yourself" [syn: {steady}, {becalm}]
     3: become quiet or calm, especially after a state of agitation;
        "After the fight both men need to cool off."; "It took a
        while after the baby was born for things to settle down
        again." [syn: {calm down}, {cool off}, {chill out}, {simmer
        down}, {settle down}, {cool it}]
     4: cause to be calm or quiet as by administering a sedative to;
        "The patient must be sedated before the operation" [syn: {sedate},
         {tranquilize}, {tranquillize}, {tranquillise}] [ant: {stimulate}]