Belch forth is a phrase that means to forcefully expel air from the stomach through the mouth, accompanied by a loud noise and sometimes with food particles. There are several synonyms for this phrase, including burp, eruct, belch, and discharge. Burp is the most commonly used synonym, which means the same as belch forth, to force out air from the stomach. Eruct is another synonym that is less common but refers to the same action. Belch, on the other hand, is another word used interchangeably with burp and belch forth. Lastly, discharge is less common and is not typically used in everyday conversations.