1) Back-up force 2) Detachment 3) Following force 4) Like some military actions 5) Military detachment 6) Military tactic 7) Stadium seat cushion 
A rearguard is that part of a military force that protects it from attack from the rear, either during an advance or withdrawal. The term can also be used to describe forces protecting lines of communication behind an army. ==Origins== The term rearguard (also rereward, rearward) originates from the medieval custom of dividing an army into three b...
A defenseman.
[n] - a detachment assigned to protect the rear of a (retreating) military body
noun a detachment assigned to protect the rear of a (retreating) military body