1. the fifth of May which is observed in Mexico and Mexican-American communities in the United States to commemorate the Mexican victory over the French in the Battle of Puebla in 1862;
WordNet (r) 3.0 (2006):
Cinco de Mayo
n 1: the fifth of May which is observed in Mexico and Mexican-
American communities in the United States to commemorate
the Mexican victory over the French in the Battle of Puebla
in 1862