furthest /ˈfɜː(ɹ)ðɪst/adverb 3adjective 2 adverb3 •To, at or over the greatest distance in space, time or other extent.Of all the children in our school, I can run furthest.He lives furthest from the office, so his commute is the longest. •To the greatest degree or extent.This civilisation was the furthest advanced. •superlative form of far: most far adjective2 •Most distant in time, space or degree.The furthest known galaxy is about 13 billion light years from Earth. •superlative form of far: most far