The Collaborative International Dictionary of English v.0.48:

Libellee \Li`bel*lee"\, n. (Law)
      (a) The party against whom a libel has been filed; --
          corresponding to defendant in a common law action.
      (b) The defendant in an action of libel.
          [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Defendant \De*fend"ant\, n.
   1. One who defends; a defender.
      [1913 Webster]

            The rampiers and ditches which the defendants had
            cast up.                              --Spotswood.
      [1913 Webster]

   2. (Law) A person required to make answer in an action or
      suit; -- opposed to plaintiff. --Abbott.
      [1913 Webster]

   Note: The term is applied to any party of whom a demand is
         made in court, whether the party denies and defends the
         claim, or admits it, and suffers a default; also to a
         party charged with a criminal offense.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Defendant \De*fend"ant\ (d[-e]*f[e^]nd"ant), a. [F.
   d['e]fendant, p. pr. of d['e]fendre. See Defend.]
   1. Serving, or suitable, for defense; defensive. [Obs.]
      [1913 Webster]

            With men of courage and with means defendant.
                                                  --Shak.
      [1913 Webster]

   2. Making defense.
      [1913 Webster]

WordNet (r) 3.0 (2006):

defendant
    n 1: a person or institution against whom an action is brought
         in a court of law; the person being sued or accused [syn:
         defendant, suspect] [ant: complainant, plaintiff]