The Collaborative International Dictionary of English v.0.48:

Marine \Ma*rine"\, n. [F. marin a sea solider, marine naval
   economy, a marine picture, fr. L. marinus. See Marine, a.]
   1. A solider serving on shipboard; a sea soldier; one of a
      body of troops trained to do duty in the navy.
      [1913 Webster]

   2. Specifically: A member of the United States Marine Corps,
      or a similar foreign military force.
      [PJC]

   3. The sum of naval affairs; naval economy; the department of
      navigation and sea forces; the collective shipping of a
      country; as, the mercantile marine.
      [1913 Webster]

   4. A picture representing some marine subject.
      [1913 Webster]

   Tell that to the marines, an expression of disbelief, the
      marines being regarded by sailors as credulous. [Colloq.]
      [1913 Webster]