1 (I, T) if you mix two or more substances or if they mix, they combine to become a single substance, and they cannot be easily separated: Mix the blue and yellow paint to make green. | Oil and water don't mix. | mix sth together/in etc: First mix the butter and sugar together, then add the milk. | mix sth with sth: Shake the bottle well so that the oil mixes with the vinegar.2 (I, T) to combine two or more different activities, ideas, groups of things etc: mix sth with sth: His books mix historical fact with fantasy. | mix business with pleasure (=combine business and social activities at the same time)3 not mix if two different ideas, activities etc do not mix, they are not suitable for each other and cause problems when they are combined: We all know that drink, drugs and knives do not mix.4 (T) to prepare something, especially food or drink, by mixing things together: Will you mix us some martinis, Bill?5 (I) to enjoy meeting, talking, and spending time with other people, especially people you do not know very well(+ with): Charlie doesn't mix well with the other children.6 (T) technical to control the balance of sounds in a record or film7 mix and match to try wearing different pieces of clothing together to see whether they look good8 mix it (up) with to argue or threaten to fight with someone: You don't want to mix it with him. He's been drinking since noon.mix sb/sth up phrasal verb (T)1 (mix someone/something up) to make the mistake of thinking that someone or something is another person or thing(+ with): I always mix him up with his brother. They look so much alike.2 (mix something up) to change the way things have been arranged, often by mistake, so that they are no longer in the same order: Don't mix up those papers, or we'll never find the ones we need.3 (mix someone up) to make someone feel confused: They kept trying to mix me up.—see also: mixed up, mixup 2 noun1 (singular) the particular combination of things or people that form a group(+ of): There's a real mix of ethnic groups in that area of the city. | We have to come up with a mix of policies to please the voters.2 (C, U) a combination of substances that you mix together to make something such as a cake: cake/soup etc mix: Add water to the cake mix and cook at 375º.mixed /mIkst/ adjective1 (only before noun) consisting of many different types of things or people: The doctor suggested a mixed diet of fruits and vegetables. | a mixed race community2 mixed reaction/response/reviews etc if something gets a mixed reaction etc, some people say they like it or agree with it, but others dislike it or disagree with it: The film has had mixed reviews from the critics.3 have mixed emotions/feelings about to be unsure about whether you like or agree with something or someone: I must admit I have rather mixed feelings about my brother's new wife.4 especially BrE for both males and females: a mixed school5 a mixed blessing something that is good in some ways but bad in others: Having your parents living nearby is a mixed blessing.6 a mixed bag a group of things or people that are all very different from each other(+ of): The concert was a mixed bag of classical and modern music.7 in mixed company when you are with people of both sexes: It's not the sort of joke you tell in mixed company.
Longman dictionary of contemporary English. 2004.