GreenwichGreen‧wich /ˈɡrenɪtʃ, ˈɡrɪnɪdʒ/ 
an area of southeast London on the River Thames. The original British Royal observatory (=a special building from which scientists watch the moon, stars etc) is there, and the 0° meridian (=an imaginary line which divides the eastern and western halves of the world) passes through the grounds of the Observatory.
an area of southeast London on the River Thames. The original British Royal observatory (=a special building from which scientists watch the moon, stars etc) is there, and the 0° meridian (=an imaginary line which divides the eastern and western halves of the world) passes through the grounds of the Observatory.