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

Synonyms & Similar Words

Relevance

Antonyms & Near Antonyms

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 network of large bases that Washington built after the 1991 Gulf War is now vulnerable to Iranian drones and ballistic missiles, offering Tehran targets and leverage rather than deterring it from taking military action.

— Philip H. Gordon, Foreign Affairs, 12 Oct. 2026
Inflation risks mount India is among the countries most vulnerable to the supply disruptions caused by the Iran war.

— Priyanka Salve, CNBC, 12 Oct. 2026

Definition of vulnerable

Adjective

If a guy who was seven for 66 in the last two postseasons and was so helpless last year that he was benched for the last three games of the World Series … if that guy can drive in the winning run from the bottom of the order?

— Los Angeles Times, Los Angeles Times, 8 Oct. 2026
The law distinguishes that from being physically helpless or incapacitated by drugs administered without consent.

— Hallie Golden, Chicago Tribune, 3 Oct. 2026

Definition of helpless

Adjective

Although generally hardy, the plant is susceptible to certain diseases, including anthracnose and bacterial soft rot, as well as pests such as spider mites, caterpillars, and whiteflies.

— Encyclopedia Britannica, Encyclopedia Britannica, 9 Oct. 2026
But neither the agency nor industry players have banned bets that could be susceptible to manipulation or raised the minimum age to bet on prediction markets to 21, the source said, up from the current minimum of 18.

— Mary Cunningham, CBS News, 8 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

See all Nearby Words

Cite this Entry

Style

“Undefended.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/undefended. Accessed 15 Oct. 2026.

Copy Citation

Synonyms of undefended

adjective

Example Sentences

Browse Nearby Words

Cite this Entry

More from Merriam-Webster

Word of the Day

outlandish

Popular in Grammar & Usage

'Affect' vs. 'Effect'

Merriam-Webster’s Great Big List of Words You Love to Hate

The Exceptions of '-s' and '-es' Plurals

Is it 'nerve-racking' or 'nerve-wracking'?

What's the difference between 'fascism' and 'socialism'?

Popular in Wordplay

16 Food Words Recently Added to the Dictionary

The Real Origin of 'Supercalifragilistic'

9 Words That Sound Like Insults But Aren't

7 Words for Bad Endings and Rough Situations

The Words of the Week - Oct. 16

Popular

'Affect' vs. 'Effect'

16 Food Words Recently Added to the Dictionary

The Real Origin of 'Supercalifragilistic'

Games & Quizzes