The Collaborative International Dictionary of English v.0.48:

Swarm \Swarm\, v. i. [imp. & p. p. Swarmed; p. pr. & vb. n.
   Swarming.]
   1. To collect, and depart from a hive by flight in a body; --
      said of bees; as, bees swarm in warm, clear days in
      summer.
      [1913 Webster]

   2. To appear or collect in a crowd; to throng together; to
      congregate in a multitude. --Chaucer.
      [1913 Webster]

   3. To be crowded; to be thronged with a multitude of beings
      in motion.
      [1913 Webster]

            Every place swarms with soldiers.     --Spenser.
      [1913 Webster]

   4. To abound; to be filled (with). --Atterbury.
      [1913 Webster]

   5. To breed multitudes.
      [1913 Webster]

            Not so thick swarmed once the soil
            Bedropped with blood of Gorgon.       --Milton.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Swarm \Swarm\, v. i. [Cf. Swerve.]
   To climb a tree, pole, or the like, by embracing it with the
   arms and legs alternately. See Shin. [Colloq.]
   [1913 Webster]

         At the top was placed a piece of money, as a prize for
         those who could swarm up and seize it.   --W. Coxe.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Swarm \Swarm\, n. [OE. swarm, AS. swearm; akin to D. zwerm, G.
   schwarm, OHG. swaram, Icel. svarmr a tumult, Sw. sv[aum]rm a
   swarm, Dan. svaerm, and G. schwirren to whiz, to buzz, Skr.
   svar to sound, and perhaps to E. swear. [root]177. Cf.
   Swerve, Swirl.]
   1. A large number or mass of small animals or insects,
      especially when in motion. "A deadly swarm of hornets."
      --Milton.
      [1913 Webster]

   2. Especially, a great number of honeybees which emigrate
      from a hive at once, and seek new lodgings under the
      direction of a queen; a like body of bees settled
      permanently in a hive. "A swarm of bees." --Chaucer.
      [1913 Webster]

   3. Hence, any great number or multitude, as of people in
      motion, or sometimes of inanimate objects; as, a swarm of
      meteorites.
      [1913 Webster]

            Those prodigious swarms that had settled themselves
            in every part of it [Italy].          --Addison.
      [1913 Webster]

   Syn: Multitude; crowd; throng.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Swarm \Swarm\, v. t.
   To crowd or throng. --Fanshawe.
   [1913 Webster]

WordNet (r) 3.0 (2006):

swarm
    n 1: a moving crowd [syn: drove, horde, swarm]
    2: a group of many things in the air or on the ground; "a swarm
       of insects obscured the light"; "clouds of blossoms"; "it
       discharged a cloud of spores" [syn: swarm, cloud]
    v 1: be teeming, be abuzz; "The garden was swarming with bees";
         "The plaza is teeming with undercover policemen"; "her mind
         pullulated with worries" [syn: teem, pullulate,
         swarm]
    2: move in large numbers; "people were pouring out of the
       theater"; "beggars pullulated in the plaza" [syn: pour,
       swarm, stream, teem, pullulate]