A "slip of the tongue" refers to an unintentional error in speech, where a person accidentally says something different from what they intended. This phenomenon can occur in everyday conversation and is often humorous or embarrassing. It may involve mispronouncing words, mixing up phrases, or using incorrect terms. These slips can happen due to various reasons, such as stress, fatigue, or distraction. Psychologists often study these occurrences to understand the complexities of language processing in the brain. The term is also related to the concept of Freudian slips, where a mistake reveals subconscious thoughts or feelings.