WordNet (r) 3.0 (2006):

America
    n 1: North American republic containing 50 states - 48
         conterminous states in North America plus Alaska in
         northwest North America and the Hawaiian Islands in the
         Pacific Ocean; achieved independence in 1776 [syn: United
         States, United States of America, America, the
         States, US, U.S., USA, U.S.A.]
    2: North America and South America and Central America

Moby Thesaurus II by Grady Ward, 1.0:

36 Moby Thesaurus words for "America":
   Africa, Antipodes, Asia, Asia Major, Asia Minor, Australasia,
   Columbia, East, Eastern Hemisphere, Eurasia, Europe, Far East,
   Land of Liberty, Levant, Middle East, Near East, New World,
   Occident, Oceania, Old World, Orient, US, USA, Uncle Sugar,
   United States, West, Western Hemisphere, Yankeeland, continent,
   down under, eastland, landmass, stateside, the States,
   the melting pot, the old country