St John'sPronunciation: /dʒɒnz/Definition of St John's 1the capital of Antigua and Barbuda, situated on the NW coast of Antigua; population 26,000 (est. 2007). 2the capital of the province of Newfoundland and Labrador, a port on the SE coast of the island; population 100,646 (2006). St John's in other Oxford dictionaries Definition of St John's in the US English dictionary