The Collaborative International Dictionary of English v.0.48:

Endurance \En*dur"ance\, n. [Cf. OF. endurance. See Endure.]
   1. A state or quality of lasting or duration; lastingness;
      continuance.
      [1913 Webster]

            Slurring with an evasive answer the question
            concerning the endurance of his own possession.
                                                  --Sir W.
                                                  Scott.
      [1913 Webster]

   2. The act of bearing or suffering; a continuing under pain
      or distress without resistance, or without being overcome;
      sufferance; patience.
      [1913 Webster]

            Their fortitude was most admirable in their patience
            and endurance of all evils, of pain and of death.
                                                  --Sir W.
                                                  Temple.

   Syn: Suffering; patience; fortitude; resignation.
        [1913 Webster]

WordNet (r) 3.0 (2006):

endurance
    n 1: the power to withstand hardship or stress; "the marathon
         tests a runner's endurance"
    2: a state of surviving; remaining alive [syn: survival,
       endurance]