Source : Webster's Revised Unabridged Dictionary (1913)

Martyr \Mar"tyr\, n. [AS., from L. martyr, Gr. ma`rtyr, ma`rtys,
   prop., a witness; cf. Skr. sm[.r] to remember, E. memory.]
   1. One who, by his death, bears witness to the truth of the
      gospel; one who is put to death for his religion; as,
      Stephen was the first Christian martyr. --Chaucer.

            To be a martyr, signifies only to witness the truth
            of Christ; but the witnessing of the truth was then
            so generally attended with persecution, that
            martyrdom now signifies not only to witness, but to
            witness by death                      --South.

   2. Hence, one who sacrifices his life, his station, or what
      is of great value to him, for the sake of principle, or to
      sustain a cause.

            Then if thou fall'st, O Cromwell, Thou fall'st a
            blessed martyr !                      --Shak.

Martyr \Mar"tyr\, v. t. [imp. & p. p. {Martyred}; p. pr. & vb.
   n. {Martyring}.]
   1. To put to death for adhering to some belief, esp.
      Christianity; to sacrifice on account of faith or
      profession. --Bp. Pearson.

   2. To persecute; to torment; to torture. --Chaucer.

            The lovely Amoret, whose gentle heart Thou martyrest
            with sorrow and with smart.           --Spenser.

            Racked with sciatics, martyred with the stone.
                                                  --Pope.

Source : WordNet®

martyr
     n 1: one who suffers for the sake of principle [syn: {sufferer}]
     2: one who voluntarily suffers death as the penalty for
        refusing to renounce their religion

martyr
     v 1: kill as a martyr; "Saint Sebastian was martyred"
     2: torture and torment like a martyr [syn: {martyrize}, {martyrise}]