The Collaborative International Dictionary of English v.0.48:

Shout \Shout\ (shout), v. i. [imp. & p. p. Shouted; p. pr. &
   vb. n. Shouting.] [OE. shouten, of unknown origin; perhaps
   akin to shoot; cf. Icel. sk[=u]ta, sk[=u]ti, a taunt.]
   1. To utter a sudden and loud outcry, as in joy, triumph, or
      exultation, or to attract attention, to animate soldiers,
      etc.
      [1913 Webster]

            Shouting of the men and women eke.    --Chaucer.
      [1913 Webster]

            They shouted thrice: what was the last cry for?
                                                  --Shak.
      [1913 Webster]

   2. To entertain with refreshments or the like gratuitously;
      to treat. [Slang, Australia & U. S.]
      [Webster 1913 Suppl.]

   To shout at, to utter shouts at; to deride or revile with
      shouts.
      [1913 Webster]