Source : Webster's Revised Unabridged Dictionary (1913)

Outfall \Out"fall`\, n.
   1. The mouth of a river; the lower end of a water course; the
      open end of a drain, culvert, etc., where the discharge
      occurs.

   2. A quarrel; a falling out. [Prov. Eng.]

Source : WordNet®

outfall
     n : the outlet of a river or drain or other source of water