The Collaborative International Dictionary of English v.0.48:

Outflow \Out*flow"\, v. i.
   To flow out. --Campbell.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Outflow \Out"flow`\, n.
   A flowing out; efflux.
   [1913 Webster]

WordNet (r) 3.0 (2006):

outflow
    n 1: the discharge of a fluid from some container; "they tried
         to stop the escape of gas from the damaged pipe"; "he had
         to clean up the leak" [syn: escape, leak, leakage,
         outflow]
    2: the process of flowing out [syn: outflow, effluence,
       efflux] [ant: inflow, influx]
    3: a natural flow of ground water [syn: spring, fountain,
       outflow, outpouring, natural spring]