Source : Webster's Revised Unabridged Dictionary (1913)

Endeavor \En*deav"or\, v. t. [imp. & p. p. {Endeavored}; p. pr.
   & vb. n. {Endeavoring}.] [OE. endevor; pref. en- + dever,
   devoir, duty, F. devoir: cf. F. se mettre en devoir de faire
   quelque chose to try to do a thing, to go about it. See
   {Devoir}, {Debt}.] [Written also {endeavour}.]
   To exert physical or intellectual strength for the attainment
   of; to use efforts to effect; to strive to achieve or reach;
   to try; to attempt.

         It is our duty to endeavor the recovery of these
         beneficial subjects.                     --Ld. Chatham.

   {To endeavor one's self}, to exert one's self strenuously to
      the fulfillment of a duty. [Obs.] ``A just man that
      endeavoreth himself to leave all wickedness.'' --Latimer.