WordNet records no synonym and no antonym for lucknow. It is the only member of each of its synsets, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a city in northern India in Uttar Pradesh; during the Indian Mutiny its British residents were besieged by Indian insurgents
the British residents of Lucknow were besieged by Indian insurgents during the Indian Mutiny (1857)
Synonyms, antonyms and the broader and narrower relations for lucknow come from Princeton University’s WordNet. Full sources and licences.