Costello

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US/kɑˈstɛloʊ/Ireland/ˈkɑstəloʊ/

proper noun

A surname from Irish.

OriginIrish Mac Oisdealbhaigh ← Latin castrum →
Less commonScrabble 10
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Meanings

proper nounCostello (countable and uncountable, plural Costellos)

plural Costellos · alternative Costilow · alternative Costley · alternative Costlow

  1. countableuncountableA surname from Irish.
  2. countableuncountableA locality in the Barkly Region, Northern Territory, Australia, named after John Costello (pastoralist).

Origin

  1. Latincastrum“fortress”
  2. IrishMac Oisdealbhaigh“son of Oisdealbhach”
  3. EnglishCostello

* As an Irish surname, reduced Anglicized form of Irish Mac Oisdealbhaigh (“son of Oisdealbhach”), a personal name composed of the elements os (“deer”) and dealbhach (“resembling, in the form of”). * As an Italian surname, Americanized from Castello. * As a Serbo-Croatian or Slovene surname, Americanized from Kostelec, Kostevc, from Kostelsko region in Lower Carniola, named after Kostel Castle, from earlier Costel, Slavicized from Latin castrum (“fortress”), hence related to the Italian above.

More words from Irish, Latin

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Cite this entry
APA

Costello. (n.d.). In WatkinsX Dictionary. Retrieved November 2, 2026, from https://dictionary.watkinsx.com/word/Costello

MLA

“Costello.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Costello. Accessed November 2, 2026.

Chicago

WatkinsX Dictionary, s.v. “Costello,” accessed November 2, 2026, https://dictionary.watkinsx.com/word/Costello.

Source: Costello on Wiktionary, CC BY-SA 4.0.