I. far ‧ thest 1 /ˈfɑːðəst, ˈfɑːðɪst $ ˈfɑːr-/ BrE AmE adverb
at or to the greatest distance away; a ↑ superlative form of ‘far’ SYN furthest :
My sister was the one who travelled farthest.
farthest away/apart etc
She lived farthest away from school of all of us.
II. farthest 2 BrE AmE adjective
[ Date: 1300-1400 ; Origin: further ]
the most distant; a ↑ superlative form of ‘far’ SYN furthest :
the farthest corners of the globe