Cast aside is a phrasal verb that means to discard or reject something or someone. There are many synonyms for this expression depending on the context in which it is used. Some popular alternatives include the words abandon, forsake, discard, reject, dismiss, discard, shun, spurn, desert, or throw away. Each of these synonyms conveys the message of disposing of something or someone, leaving it behind, or moving on from it. The usage of these synonyms can help to add variety to your writing or speech and enable you to convey your message more effectively.