Source : Webster's Revised Unabridged Dictionary (1913)

Wall Street \Wall Street\
   A street towards the southern end of the borough of
   Manhattan, New York City, extending from Broadway to the East
   River; -- so called from the old wall which extended along it
   when the city belonged to the Dutch. It is the chief
   financial center of the United States, hence the name is
   often used for the money market and the financial interests
   of the country.

Source : WordNet®

Wall Street
     n 1: a street in lower Manhattan where the New York Stock
          Exchange is located; symbol of American finance [syn: {Wall
          St.}]
     2: used to allude to the securities industry of the United
        States [syn: {the Street}]