Definition of arrière-guard in US English:

arrière-guard

noun

  • 1Military. The rear division of an army or fleet drawn up for action; (also) a body of troops detached from the main force to bring up and protect the rear; = "rearguard". Now chiefly historical.

  • 2Usually in form arrière-garde. A group of people holding cautious, conformist, or outdated opinions; conservatives or traditionalists, especially in the arts, regarded collectively.

adjective

  • Usually in form arrière-garde. In the arts: representative of the arrière-garde, conservative, reactionary; conventional, traditional.

Origin

Late 15th century; earliest use found in William Caxton (1415x24–1492), printer, merchant, and diplomat. From Anglo-Norman arer-garde, Middle French arriere-garde, ariere-garde, arrer-garde from arere behind + guarde.

Pronunciation

arrière-guard

/ˌarɪɛːˈɡɑːd/