Source : Webster's Revised Unabridged Dictionary (1913)

Expulsion \Ex*pul"sion\, n. [L. expulsio, fr. expellere: cf. F.
   expulsion. See {Expel}.]
   1. The act of expelling; a driving or forcing out; summary
      removal from membership, association, etc.

            The expulsion of the Tarquins.        --Shak.

   2. The state of being expelled or driven out.

Source : WordNet®

expulsion
     n 1: the act of forcing out someone or something; "the ejection
          of troublemakers by the police"; "the child's expulsion
          from school" [syn: {ejection}, {exclusion}, {riddance}]
     2: squeezing out by applying pressure; "an unexpected extrusion
        of toothpaste from the bottom of the tube"; "the expulsion
        of pus from the pimple" [syn: {extrusion}]
     3: the act of expelling or projecting or ejecting [syn: {projection},
         {ejection}, {forcing out}]