Marble ArchPronunciation: /mɑːblˈɑːtʃ/Entry from World dictionaryDefinition of Marble Arch a large arch with three gateways at the NE corner of Hyde Park in London. Designed by John Nash, it was erected in 1827 in front of Buckingham Palace and moved in 1851 to its present site. Marble Arch in other Oxford dictionaries Definition of Marble Arch in the British & World English dictionary