Saint Thomas (s?nt) An island of the US Virgin Islands in the West Indies east of Puerto Rico. Sighted and named by Columbus in 1493, it was settled by the Dutch in 1657 and later passed to the Danes, who sold it to the United States in 1917.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.Saint Thomas n 1. (Placename) an island in the E Caribbean, in the Virgin Islands of the US. Capital: Charlotte Amalie. Pop: 51 181 (2000). Area: 83 sq km (28 sq miles) 2. (Placename) the former name (1921?37) of Charlotte Amalie Usually abbreviated to: St ThomasCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014