The term 'RELY' is a four-letter word that means to put trust in. It is derived from the Middle English word 'relien, ' which means to lean on or depend on. RELY is often used in the context of trusting someone or something, such as relying on a friend for support or relying on a product to work properly. It can also be used to express faith in a certain outcome, such as relying on a good outcome in a difficult situation.