Cast forth is a phrase often used in literature and language to describe the act of throwing something out, such as an idea or emotion. Synonyms for cast forth include expel, eject, release, discard, and throw out. These words all convey the idea of forcibly removing something from one's body or possession and discarding it. Another synonym for cast forth is to emit, which is often used to describe a release of energy or sound. Using synonyms for cast forth can help writers add variety and depth to their vocabulary, making their writing more interesting and engaging.