market vs the City

market and the City both are nouns.

Word	Noun	Adjective	Verb	Adverb
market	Yes	No	Yes	No
the City	Yes	No	No	No

As nouns, the City is a hyponym of market; that is, the City is a word with a more specific, narrower meaning than market:

Other hyponyms of market include bear market, bull market, the Street, Wall Street, money market.

market (noun)	the City (noun)
the world of commercial activity where goods and services are bought and sold	used to allude to the securities industry of Great Britain
a marketplace where groceries are sold	the part of London situated within the ancient boundaries; the commercial and financial center of London
an area in a town where a public mercantile establishment is set up
the customers for a particular product or service
the securities markets in the aggregate

market (verb)	the City (verb)
make commercial
engage in the commercial promotion, sale, or distribution of
deal in a market
buy household supplies