endeavor

Concise Oxford English Dictionary © 2008 Oxford University Press:
endeavour /ɪnˈdɛvə, ɛn-/ (US endeavor)

▶verb try hard to do or achieve. ▶noun

• 1 an act of endeavouring; an enterprise.

• 2 earnest and industrious effort.

– origin ME: from the phr. put oneself in devoir ‘do one's utmost’ (see devoir).