The Collaborative International Dictionary of English v.0.48:

Fresh-water \Fresh"-wa`ter\, a.
   1. Of, pertaining to, or living in, water which is not salty;
      as, fresh-water geological deposits; a fresh-water fish;
      fresh-water mussels.
      [1913 Webster]

   2. Accustomed to sail on fresh water only; unskilled as a
      seaman; as, a fresh-water sailor.
      [1913 Webster]

   3. Unskilled; raw. [Colloq.] "Fresh-water soldiers."
      --Knolles. Fresnel lamp

WordNet (r) 3.0 (2006):

freshwater
    n 1: water that is not salty [syn: fresh water, freshwater]
         [ant: brine, saltwater, seawater]