The ordinal number of forty-eight in counting order(adjective)
WordNet. Princeton University. 2010.
Use "48th" in a sentence
"A few days later the New York Times told us that the World Economic Forum ranked the U.S. 48th, out of 133 developed nations, in the quality of math and science instruction. “48th is not a good place,” said the Times."
"The one on 48th is getting more crowded and chaotic, which leads to longer waits and more potential mix-ups."
"The name has been accepted and alternates with the "48th" in describing this corps."