nor ‧ thern ‧ most /ˈnɔːð ə nməʊst $ ˈnɔːrðərnmoʊst/ BrE AmE adjective
[ Word Family: adjective : ↑ north , ↑ northerly , ↑ northern , ↑ northbound , ↑ northernmost , ↑ northward ; noun : ↑ north , ↑ northerner ; adverb : ↑ north , northward(s)]
furthest north:
the northernmost tip of the island