ˌRoyal ˌGreenwich Obˈservatory, the BrE AmE
the British national ↑ observatory (=a place where scientists study the stars) , which was established in the 17th century, in ↑ Greenwich , South London. After World War II the observatory moved to Cambridge, but it closed in 1998. The 0°↑ meridian (=an imaginary line that divides the east part of the world from the west) passes through the building in Greenwich, which is now part of the National Maritime Museum. ⇨ ↑ Greenwich Mean Time