Source : Webster's Revised Unabridged Dictionary (1913)

Upwind \Up*wind"\, v. t.
   To wind up. --Spenser.

Source : WordNet®

upwind
     adj : towards the side exposed to wind [syn: {weather(a)}]
     adv 1: toward the wind; "they were sailing leeward" [syn: {leeward}]
            [ant: {windward}, {windward}]
     2: in the direction opposite to the direction the wind is
        blowing; "they flew upwind" [syn: {against the wind}, {into
        the wind}] [ant: {downwind}]