Real Dictionary

siesta
countable noun: A siesta is a short sleep or rest which you have in the early afternoon, especially in hot countries.

siesta in American English
a brief nap or rest taken after the noon meal, esp. in Spain and some Latin American countries
noun: a midday or afternoon rest or nap, esp. as taken in Spain and Latin America

siesta in British English
noun: a rest or nap, usually taken in the early afternoon, as in hot countries