In American military matters, that exposed part of the army that is nearest to Congress.
The back or hindmost part; that which is behind, or last in order; -- opposed to front.
Specifically, the part of an army or fleet which comes last, or is stationed behind the rest.
Being behind, or in the hindmost part; hindmost; as, the rear rank of a company.
the back of a military formation or procession; "infantrymen were in the rear"
the part of something that is furthest from the normal viewer; "he stood at the back of the stage"; "it was hidden in the rear of the store"
The direction away from the enemy.
interior, away from the enemy.
In military parlance, the rear is the part of concentration of military forces that is furthest from the enemy (compare its antonym, the front line). The rear typically contains all elements of the force necessary to support combat forces - food, medical supplies and substantial shelters, planners and command headquarters.