From Longman Dictionary of Contemporary EnglishElementary, my dear Watson.my dear Watson. ElementaryElementary, my dear Watson.people sometimes use this expression humorously to say how easy something is to solve. Some people think that the phrase comes from the Sherlock Holmes stories by Sir Arthur Conan Doyle. Holmes says this to his friend Watson when explaining how easy it is to understand something about a crime. In fact, the phrase does not appear in the books. → elementary
