Greenwich1 a London borough on the south bank of the Thames, the original site of the Royal Greenwich Observatory. The buildings at Greenwich, together with many of the old instruments, now form part of the National Maritime Museum, and reclaimed land at Greenwich forms the site of the Millennium Dome.
Greenwich Mean Time the mean solar time at the Greenwich meridian, adopted as the standard time in a zone that includes the British Isles.
Greenwich meridian the prime meridian, which passes through the former Royal Observatory at Greenwich. It was adopted internationally as the zero of longitude in 1884.

Greenwich Borough in se London, England. The former Royal Observatory (founded 1675) is in Greenwich Park. The prime meridian forms the basis of Greenwich Mean Time (GMT). Greenwich has a rich maritime history. The Royal Naval College, partly designed (1696) by Sir Christopher Wren, stands on the site of a Tudor royal palace, birthplace of Henry VIII. The Millennium Dome was built here to celebrate the dawning of the third millennium. Pop. (1997 est.) 215,300.

Greenwich2 Greenwich Village a district of New York City on the lower west side of Manhattan, traditionally associated with writers, artists, and musicians.