The rearmost part of a force, especially a detachment of troops that protect the rear of a retreating force.(noun)
The defence, collectively the defenders.(noun)
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Use "rearguard" in a sentence
"Still bedding in together, the Arsenal manager sees in them the foundations of a new, long-term rearguard."
"Even after the feminist revolution nepotism continues to play a role in rearguard efforts to preserve the male monopoly on power."
"England's defence was the one part of the team to impress in Denmark but with players such as Chris Smalling and Phil Jones having outgrown this level, the rearguard was the focus of most of Pearce's rebuilding here, with three of the four players starting for the first time being defenders and the other the goalkeeper, Jack Butland of Birmingham City."