lon ‧ gi ‧ tude /ˈlɒndʒətjuːd, ˈlɒndʒɪtjuːd $ ˈlɑːndʒətuːd/ BrE AmE noun [uncountable and countable]
[ Date: 1300-1400 ; Language: Latin ; Origin: longitudo 'length' , from longus 'long' ]
the distance east or west of a particular ↑ meridian (=imaginary line along the Earth’s surface from the North Pole to the South Pole) , measured in degrees ⇨ latitude :
The town lies at longitude 12° east.