Endeavor (?), 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.
[1913 Webster]

It is our duty to endeavor the recovery of these beneficial subjects. Ld. Chatham.
[1913 Webster]

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.
[1913 Webster]

Endeavor, n. [Written also endeavour.] An exertion of physical or intellectual strength toward the attainment of an object; a systematic or continuous attempt; an effort; a trial.
[1913 Webster]

To employ all my endeavor to obey you. Sir P. Sidney.
[1913 Webster]

To do one's endeavor, to do one's duty; to put forth strenuous efforts to attain an object; -- a phrase derived from the Middle English phrase “to do one's dever” (duty). “Mr. Prynne proceeded to show he had done endeavor to prepare his answer.” Fuller.

Syn. -- Essay; trial; effort; exertion. See Attempt.
[1913 Webster]