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"Centenares" is a form of "centenar", a noun which is often translated as "hundred". "Cientos" is a form of "cientos", a plural noun which is often translated as "hundreds". Learn more about the difference between "centenares" and "cientos" below.
el centenar(
sehn
-
teh
-
nahr
)A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
1. (quantity)
a. hundred
El primer centenar de personas que llegue al estadio recibirán una gorra gratis.The first hundred people to arrive at the stadium will receive a free cap.