The Collaborative International Dictionary of English v.0.48:

Peso \Pe"so\, n. [Sp.]
   A Spanish dollar; also, an Argentine, Chilian, Colombian,
   etc., coin, equal to from 75 cents to a dollar; also, a pound
   weight.
   [1913 Webster]

WordNet (r) 3.0 (2006):

peso
    n 1: the basic unit of money in Uruguay; equal to 100 centesimos
         [syn: Uruguayan peso, peso]
    2: the basic unit of money in the Philippines; equal to 100
       centavos [syn: Philippine peso, peso]
    3: the basic unit of money in Mexico; equal to 100 centavos
       [syn: Mexican peso, peso]
    4: the basic unit of money in Guinea-Bissau; equal to 100
       centavos [syn: Guinea-Bissau peso, peso]
    5: the basic unit of money in the Dominican Republic; equal to
       100 centavos [syn: Dominican peso, peso]
    6: the basic unit of money in Cuba; equal to 100 centavos [syn:
       Cuban peso, peso]
    7: the basic unit of money in Colombia; equal to 100 centavos
       [syn: Colombian peso, peso]
    8: the basic unit of money in Chile; equal to 100 centesimos
       [syn: Chilean peso, peso]