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English definition of “complex”

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complex

adjective uk   /ˈkɒm.pleks/ /kəmˈpleks/ us    /ˈkɑːm-/
B2 involving a lot of different but related parts: a complex molecule/carbohydrate a complex network of roads a complex procedure The company has a complex organizational structure.B2 difficult to understand or find an answer to because of having many different parts: It's a very complex issue to which there is no straightforward answer. The film's plot was so complex that I couldn't follow it.
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complex

noun [C] uk   /ˈkɒm.pleks/ us    /ˈkɑːm-/

complex noun [C] (BUILDING)

C1 a large building with various connected rooms or a related group of buildings: a shopping/sports and leisure complex US They live in a large apartment complex.
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complex noun [C] (BAD FEELING)

C2 a particular anxiety or unconscious fear that a person has, especially as a result of an unpleasant experience that they have had in the past or because they have a low opinion of their own worth: an inferiority complex I think he's got a complex about being bald. Don't go on about her weight - you'll give her a complex!
(Definition of complex from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
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