Opposite Indicator is a term used to describe a word or phrase that has the opposite meaning of another word or phrase. It is often used in language to express the opposite of something. Not and non are two of the most common opposite indicators. Not is a three-letter word that is used to express the opposite of something, while non is also a three-letter word that is used to express the opposite of something. Both words can be used to indicate the opposite of something, but they have slightly different meanings. Not implies a complete negation of something, while non implies a partial negation.