adverb to or at a greater extent or degree or a more advanced stage (`further' is used more often than `farther' in this abstract sense).
— synonyms: further
adverb to or at a greater distance in time or space (`farther' is used more frequently than `further' in this physical sense).
— synonyms: further
adjective more distant in especially space or time.
adjective more distant in especially degree.
— synonyms: further