rear‧guard /ˈrɪəɡɑːd $ ˈrɪrɡɑːrd/ noun
[Date: 1400-1500; Language: Old French; Origin: reregarde, from rere 'behind' (from Latin retro-) + garde 'guard']

1. fight a rearguard action
a) to make a determined effort to prevent a change that you think is bad, although it seems too late to stop it:
They have been fighting a rearguard action to stop a supermarket being built on the land.
b) if an army fights a rearguard action, it defends itself at the back against an enemy that is chasing it

2. [singular] the group of soldiers who defend the back of an army against an enemy that is chasing it

[TahlilGaran] Dictionary of Contemporary English ▲