Source : Webster's Revised Unabridged Dictionary (1913)

Suck \Suck\, v. t. [imp. & p. p. {Sucked}; p. pr. & vb. n.
   {Sucking}.] [OE. suken, souken, AS. s?can, s?gan; akin to D.
   zuigen, G. saugen, OHG. s?gan, Icel. s?ga, sj?ga, Sw. suga,
   Dan. suge, L. sugere. Cf. {Honeysuckle}, {Soak}, {Succulent},
   {Suction}.]
   1. To draw, as a liquid, by the action of the mouth and
      tongue, which tends to produce a vacuum, and causes the
      liquid to rush in by atmospheric pressure; to draw, or
      apply force to, by exhausting the air.

   2. To draw liquid from by the action of the mouth; as, to
      suck an orange; specifically, to draw milk from (the
      mother, the breast, etc.) with the mouth; as, the young of
      an animal sucks the mother, or dam; an infant sucks the
      breast.

   3. To draw in, or imbibe, by any process resembles sucking;
      to inhale; to absorb; as, to suck in air; the roots of
      plants suck water from the ground.

   4. To draw or drain.

            Old ocean, sucked through the porous globe.
                                                  --Thomson.

   5. To draw in, as a whirlpool; to swallow up.

            As waters are by whirlpools sucked and drawn.
                                                  --Dryden.

   {To suck in}, to draw into the mouth; to imbibe; to absorb.
      

   {To suck out}, to draw out with the mouth; to empty by
      suction.

   {To suck up}, to draw into the mouth; to draw up by suction
      or absorption.

Sucking \Suck"ing\, a.
   Drawing milk from the mother or dam; hence, colloquially,
   young, inexperienced, as, a sucking infant; a sucking calf.

         I suppose you are a young barrister, sucking lawyer, or
         that sort of thing.                      --Thackeray.

   {Sucking bottle}, a feeding bottle. See under {Bottle}.

   {Sucking fish} (Zo["o]l.), the remora. See {Remora}. --Baird.

   {Sucking pump}, a suction pump. See under {Suction}.

   {Sucking stomach} (Zo["o]l.), the muscular first stomach of
      certain insects and other invertebrates which suck liquid
      food.

Source : WordNet®

sucking
     n : the act of sucking [syn: {suck}, {suction}]