Alternative form of further.
"The farther you go into the forest, the harder it becomes to find your way back."
In plain English: Farther is not actually used as a verb; it is only an adjective meaning further away, while its related word farthest describes the point furthest from something else.
"The dog ran farther when he heard the squirrel squeaking in the tree."
Alternative form of further. (See also the usage notes at further.)
"The farther you drive into the desert, the hotter it gets."
In plain English: Farther means being at a greater physical distance from where you are now.
"The farther hills were covered in thick fog."
to or at a greater extent or degree or a more advanced stage (`further' is used more often than `farther' in this abstract sense)
"further complicated by uncertainty about the future"
"let's not discuss it further"
"nothing could be further from the truth"
"they are further along in their research than we expected"
"the application of the law was extended farther"
"he is going no farther in his studies"
to or at a greater distance in time or space (`farther' is used more frequently than `further' in this physical sense)
"farther north"
"moved farther away"
"farther down the corridor"
"the practice may go back still farther to the Druids"
"went only three miles further"
"further in the future"
Alternative form of further. (See also the usage notes at further.)
"The committee decided to take farther steps to address the budget deficit, though some members preferred the word further."
In plain English: Farther means moving to a place that is physically more distant from where you started.
"The train ride to Chicago is much farther than our trip to Detroit."
Farther is a variant spelling of further that developed to specifically indicate physical distance rather than abstract degree. It entered common usage as English speakers sought to distinguish between moving farther away and going further along an idea or process.