"Further" is an adverb that indicates a greater distance in space or time. It can also refer to an increase in degree or extent, such as "further research" or "further discussion." In this context, it suggests moving beyond what has already been established or known. In addition to its adverbial use, "further" can function as a verb meaning to advance or promote something. For example, one might "further" a cause or project, indicating efforts to help it progress. This usage emphasizes the action of making something more developed or successful.