CONCENTRATION

[noun]He strongly opposed the concentration (= existence of a large amount) of power in the hands of so few people. [U]There is a (heavy) concentration (= gathering) of troops in the area. [C]Concentrations (= Groups) of police became apparent as they drove further into the town. [C](specialized) Concentration is the exact amount of one particular substance that is found in another substance.a concentration of one part per million [C]High concentrations of toxic elements were found in the polluted areas of the sea. [C]A study is under way to determine the exact concentration of lead in the local water supply. [U]A concentration camp is a prison where people are kept in extremely bad conditions, esp. for political reasons.During World War II, millions of Jews died in Nazi concentration camps.