"Rej" is a slang term that is often used to describe the act of rejecting someone or something. There are several synonyms for this term that can be used to convey the same meaning. Some of the most commonly used synonyms for "rej" include words such as decline, deny, refuse, dismiss, repudiate, spurn, and turn down. Each of these words can be used in a variety of contexts to express different shades of meaning when it comes to rejecting something or someone. Whether you're turning down a business proposal or rejecting a romantic advance, there's sure to be a synonym for "rej" that will help you communicate your message clearly and effectively.