Meaning of COMPLEX in English
(HAVING MANY PARTS) [adjective] - involving a lot of different but related partsa complex molecule/carbohydratea complex subject/theorya complex network of roadsThe operation is a very complex procedure.The company has a complex organizational structure.Complex can also mean difficult to understand or find an answer to because of having many different parts.It's a very complex issue/problem/matter to which there is no straightforward answer.The film's plot was so complex that I couldn't follow it.She has a very complex personality and sometimes I feel I don't know her at all.(specialized) In grammar, a complex sentence is one which contains a main part and one or more other parts.'If he asks me, I'll marry him' is a complex sentence containing the main clause, 'I'll marry him', and another clause, 'If he asks me'.(specialized) A complex word is a word consisting of a main part and one or more other parts.The word 'hopeful' is a complex word of which 'hope' is the main part and 'ful' is an added ending.
Cambridge English vocab. Кембриджский английский словарь. 2012