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.
How many Catholics are in United States? According to the 2010 data from the Pew Research Center, there are  about 75,380, 000 Catholics in the United States of America.   With more than 77 million faithful, it â¦is the largest single  religious group in the USA, comprising 25 percent of the  population.