Launch forth is a verb phrase that indicates the act of beginning or starting something new. There are various synonyms for this phrase, including initiate, commence, start, begin, embark on, set out, undertake, inaugurate, kick off, and open. These synonyms convey the idea of introducing a new activity, project, or venture, and can be used interchangeably depending on the context. For instance, one can use "initiate" or "kick off" in a sporting event, "embark on" or "commence" in a business project, or "set out" or "begin" in an adventurous journey. Overall, all these synonyms mean the same thing, which is to embark on a new venture or activity with enthusiasm and purpose.