A malapropism is a language mistake that occurs when a person uses a word that sounds similar to the correct word but has a completely different meaning. This often leads to humorous or nonsensical statements. The term comes from the character Mrs. Malaprop in the 18th-century play "The Rivals" by Richard Brinsley Sheridan, who frequently misused words. Malapropisms can happen in everyday conversation and are often unintentional. They highlight the importance of vocabulary and understanding word meanings. Common examples include saying "He is the pineapple of politeness" instead of "He is the pinnacle of politeness."