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

suck \suck\ su^k, v. t. imp.  p. p. sucked su^kt; p.
   pr.  vb. n. sucking. oe. suken, souken, as. s=ucan,
   s=ugan; akin to d. zuigen, g. saugen, ohg. s=ugan, icel.
   s=uga, sj=uga, 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.
      1913 webster

   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.
      1913 webster

   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.
      1913 webster

   4. to draw or drain.
      1913 webster

            old ocean, sucked through the porous globe.
                                                  --thomson.
      1913 webster

   5. to draw in, as a whirlpool; to swallow up.
      1913 webster

            as waters are by whirlpools sucked and drawn.
                                                  --dryden.
      1913 webster

   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.
      1913 webster
see also:
sucked sucking honeysuckle soak succulent suction 
to suck in to suck out to suck up 

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

sucking \suck"ing\, a.
   drawing milk from the mother or dam; hence, colloquially,
   young, inexperienced, as, a sucking infant; a sucking calf.
   1913 webster

         i suppose you are a young barrister, sucking lawyer, or
         that sort of thing.                      --thackeray.
   1913 webster

   sucking bottle, a feeding bottle. see under bottle.

   sucking fish zool., the remora. see remora. --baird.

   sucking pump, a suction pump. see under suction.

   sucking stomach zool., the muscular first stomach of
      certain insects and other invertebrates which suck liquid
      food.
      1913 webster
see also:
sucking bottle bottle sucking fish remora sucking pump suction 
sucking stomach 

[3] : WordNet (r) 2.0

sucking
     n : the act of sucking syn: suck, suction
see also:
suck suction 

Sucking >> S Words
Sucking, definition of term: Sucking
sucking_pag1.html

Cock Sucking >> C Words
Cock Sucking, definition of term: Cock Sucking
cock+sucking_pag1.html