The Collaborative International Dictionary of English v.0.48:

Sever \Sev"er\, v. t. [imp. & p. p. Severed; p. pr. & vb. n.
   Severing.] [OF. sevrer, severer, to separate, F. sevrer to
   wean, fr. L. separare. See Separate, and cf. Several.]
   1. To separate, as one from another; to cut off from
      something; to divide; to part in any way, especially by
      violence, as by cutting, rending, etc.; as, to sever the
      head from the body.
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            The angels shall come forth, and sever the wicked
            from among the just.                  --Matt. xiii.
                                                  49.
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   2. To cut or break open or apart; to divide into parts; to
      cut through; to disjoin; as, to sever the arm or leg.
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            Our state can not be severed; we are one. --Milton.
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   3. To keep distinct or apart; to except; to exempt.
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            I will sever in that day the land of Goshen, in
            which my people dwell, that no swarms of flies shall
            be there.                             --Ex. viii.
                                                  22.
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   4. (Law) To disunite; to disconnect; to terminate; as, to
      sever an estate in joint tenancy. --Blackstone.
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WordNet (r) 3.0 (2006):

severing
    n 1: the act of severing [syn: severance, severing]