IPA: /ˈfɑːrðərmoʊst/
KK: /ˈfɑrðərˌmoʊst/
The most distant point or location from a reference point.
The farthermost star in the galaxy is billions of light-years away from Earth.
Farthermost is formed from "farther" (an adverb meaning to a greater distance, derived from Old English "further", meaning more distant) and "-most" (a superlative suffix meaning the most or the furthest). The word "farthermost" means the most distant or the furthest away.
Think of 'farther' as indicating a greater distance and '-most' as meaning the extreme or highest degree. This helps you remember that 'farthermost' refers to the greatest distance.