a character in the playTwelfth Night by William Shakepeare. Malvolio is one of Olivia's servants, and the people in Olivia's house play a trick on him by telling him that Olivia loves him. He then tries to begin a romantic relationship with her, but behaves so strangely that people think he is crazy and put him in prison.
Definition from the Longman Dictionary of Contemporary English Advanced Learner's Dictionary.