[1] : The Collaborative International Dictionary of English v.0.48

rear \rear\, a.
   being behind, or in the hindmost part; hindmost; as, the rear
   rank of a company.
   1913 webster

   rear admiral, an officer in the navy, next in rank below a
      vice admiral and above a commodore. see admiral.

   rear front mil., the rear rank of a body of troops when
      faced about and standing in that position.

   rear guard mil., the division of an army that marches in
      the rear of the main body to protect it; -- used also
      figuratively.

   rear line mil., the line in the rear of an army.

   rear rank mil., the rank or line of a body of troops
      which is in the rear, or last in order.

   rear sight firearms, the sight nearest the breech.

   to bring up the rear, to come last or behind.
      1913 webster
see also:
rear admiral admiral rear front rear guard rear line rear rank 
rear sight to bring up the rear 

[2] : WordNet (r) 2.0

rear admiral
     n : an admiral junior to a vice admiral

Rear Admiral >> R Words
Rear Admiral, definition of term: Rear Admiral
rear+admiral_pag1.html

Rear >> R Words
Rear, definition of term: Rear
rear_pag1.html

Admiral >> A Words
Admiral, definition of term: Admiral
admiral_pag1.html

Rear Back >> R Words
Rear Back, definition of term: Rear Back
rear+back_pag1.html