Fiesta

google

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Spanish, from Latin festum, (plural) festa (see feast).

wiktionary

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Borrowed from Spanish fiesta, from Late Latin festa, from the plural of festum(“feast”). Doublet of feast and fete.

etymonline

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fiesta (n.)

1844 as a Spanish word in English, "Spanish-American religious festival," Spanish, literally "feast" (see feast (n.)).