Source : Webster's Revised Unabridged Dictionary (1913)

Seaman \Sea"man\, n.; pl. {Seamen}. [AS. s[ae]man.]
   One whose occupation is to assist in the management of ships
   at sea; a mariner; a sailor; -- applied both to officers and
   common mariners, but especially to the latter. Opposed to
   {landman}, or {landsman}.

   {Able seaman}, a sailor who is practically conversant with
      all the duties of common seamanship.

   {ordinary seaman}. See {Ordinary}.

Source : WordNet®

able seaman
     n : a seaman in the merchant navy; trained in special skills
         [syn: {able-bodied seaman}]