Webster Dictionary(0.00 / 0 votes)Rate this definition: 1  Hypo-. a prefix signifying a less quantity, or a low state or degree, of that denoted by the word with which it is joined, or position under or beneath. 2  Hypo-.
Confidence votes 25. St Patrick's Cathedral in New York City. ***Actually, the Basilica of the National Shrine of the Immaculate Conception in DC is larger than St. Patrick's in NYC. The National Shrine is the largest Roman Catholic church in the U.S., and one of the 10 largest Roman Catholic churches in the world.
The largest religion in the US is Christianity, claimed by the majority of the population (70.6% in 2014). According to the Association of Statisticians of American Religious Bodies newsletter published March, 2017, based on data from 2010, Christians were the largest religion in all 3143 counties in the country.