UNDEFENDED Synonyms: 49 Similar and Opposite Words

undefended

adjective

ˌən-di-ˈfen-dəd

Definition of undefended

as in vulnerable

lacking protection from danger or resistance against attack the cowardly soldiers fled, leaving the palace undefended

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Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

Recent Examples of undefended The lack of range of Coastal Command aircraft left an undefended area known as the Mid-Atlantic Gap, rendering merchant shipping and their escorts without air cover and vulnerable to attack. — Mark Wood, TheWeek, 7 Jan. 2026 Trouba opened the scoring in the first period with an undefended slap shot after an egregious Blackhawks turnover. — CBS News, 7 Dec. 2025 Mark Collins, who was born and raised in Newfoundland, Canada, said Canadians have long treasured their friendship with the United States and the fact that the US-Canada border is the longest undefended border on the planet. — Matt Egan, CNN Money, 13 Oct. 2025 Like the global undersea cable network, the United States’ deep-water drilling infrastructure is rapidly expanding while remaining almost entirely undefended. — Robert Martinage, Foreign Affairs, 1 Jan. 2015 See All Example Sentences for undefended

Recent Examples of Synonyms for undefended

Adjective

The model examined the website, found a vulnerable script and used it to complete the calculation.

— Kurt Knutsson, FOXNews.com, 19 Oct. 2026
Focusing on low income nations and vulnerable populations has been a defining thread throughout Georgieva's career.

— , CNBC, 19 Oct. 2026

Definition of vulnerable

Adjective

The moment when the couple’s infant child is taken from them by the authorities is devastating, each of them capturing a sense of helpless isolation from themselves, their community and each other.

— Mark Olsen, Los Angeles Times, 9 Oct. 2026
But the funding cuts mean more and more families like Zarmina's are left helpless.

— ABC News, ABC News, 4 Oct. 2026

Definition of helpless

Adjective

Tom describes himself as uniquely susceptible to this kind of stimulation, something that Kenny, the Mount Sinai neuroscientist, says may have some credence.

— Allison Parshall, Scientific American, 20 Oct. 2026
The United States also has a uniquely large and diverse economy that is far less susceptible to shocks than many of its smaller peers.

— David Goldman, CNN Money, 20 Oct. 2026

Definition of susceptible

Adjective

However, the fibers cannot simply be dropped into the ocean unprotected.

— Kaif Shaikh, Interesting Engineering, 13 Oct. 2026
However, during the same season, more than a third of the state’s children went unprotected, and many older Marylanders eligible for the RSV vaccine never received it.

— Adejare Atanda, Baltimore Sun, 13 Oct. 2026

Definition of unprotected

Browse Nearby Words

undefeated

undefended

undefiled

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“Undefended.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/undefended. Accessed 21 Oct. 2026.

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Synonyms of undefended

adjective

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