concentration camp

noun3

1. •
   A camp where large numbers of people, especially political prisoners, prisoners of war, refugees etc., are detained for the purpose of confining them in one place, typically with inadequate or inhumane facilities.

   • All Cubans (men, women, and children) were ordered to move into garrisoned Spanish towns or concentration camps. — 1927
2. •
   (figurative) A situation of overcrowding and extremely harsh conditions.

   • The UN inspector stated that the Australian government's migrant detention facilities were in effect concentration camps.
3. •
   A camp where troops are assembled, prior to combat or transport.

   • The 21st Lancers… …journey forward by nine days' march to the advanced concentration camp just north of the Shabluka Cataract. — 1930