Source : Webster's Revised Unabridged Dictionary (1913)

   2. The sum of naval affairs; naval economy; the department of
      navigation and sea forces; the collective shipping of a
      country; as, the mercantile marine.

   3. A picture representing some marine subject.

   {Tell that to the marines}, an expression of disbelief, the
      marines being regarded by sailors as credulous. [Colloq.]