farthermost

from WordNet (r) 3.0 (2006)

farthermost
    adj 1: (comparatives of `far') most remote in space or time or
           order; "had traveled to the farthest frontier"; "don't go
           beyond the farthermost (or furthermost) tree"; "explored
           the furthest reaches of space"; "the utmost tip of the
           peninsula" [syn: {farthermost}, {farthest},
           {furthermost}, {furthest}, {utmost}, {uttermost}]

from The Collaborative International Dictionary of English v.0.48

Farthermost \Far"ther*most`\, a.
   Most remote; farthest.
   [1913 Webster]