The Collaborative International Dictionary of English v.0.48:

Down-wind \Down"-wind`\, adv.
   With the wind.
   [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

downwind \down"wind\ adj.
   on the side or in the direction away from the direction from
   which the wind is blowing; in the direction toward which the
   wind is blowing; as, good hunters stay downwind of their
   prey. Opposite of upwind, and windward.

   Syn: lee(prenominal), leeward.
        [WordNet 1.5]