形容詞 farthest:

1. (comparatives of `far') most remote in space or time or order
   同義詞：farthermost, furthermost, furthest, utmost, uttermost

副詞 farthest:

1. to the greatest distance in space or time (`farthest' is used more often than `furthest' in this physical sense)
   同義詞：furthest
2. to the greatest degree or extent or most advanced stage (`furthest' is used more often than `farthest' in this abstract sense)
   同義詞：furthest

1. It's ten miles away, at the farthest.
   最遠不超過十英里。
2. Go to the farthest house in the village and I'll meet you there.
   到村上最遠的那座房子那兒去，我在那里與你會面。
3. Who ran (the) farthest?
   誰跑得最遠?
4. The farthest distance I've run is ten miles.
   我跑過的最長的距離是十英里。
5. She is the farthest advanced of all my students.
   她是我所有學生中學習最好的。

far.thest

adj.（形容詞）
far的最高級
Most remote or distant.
最遠的
adv.（副詞）
far的最高級
To or at the most distant or remote point.
最遠地：到或在最遠距離或最遠點地
To or at the most advanced point or stage.
到或在最高點或階段地
By the greatest extent or degree.
最大限度地，最大程度地

來源：
Middle English ferthest [superlative of] farther * see farther
中古英語 ferthest [] farther的最高級 *參見 farther