unconstitutional

adjective

un·​con·​sti·​tu·​tion·​al ˌən-ˌkän(t)-stə-ˈtü-sh(ə-)nəl How to pronounce unconstitutional (audio)
-ˈtyü-
Synonyms of unconstitutionalnext
: not according or consistent with the constitution of a body politic (such as a nation)
an unconstitutional infringement on rights
unconstitutionality
ˌən-ˌkän(t)-stə-ˌtü-shə-ˈna-lə-tē How to pronounce unconstitutional (audio)
-ˌtyü-
noun
unconstitutionally adverb

Examples of unconstitutional in a Sentence

an unconstitutional infringement of rights The law may be unconstitutional.
Recent Examples on the Web
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.
Federal courts considering the order have already found core sections legally void, ultra vires and likely unconstitutional, concluding that the executive branch has no authority to unilaterally redesign mail voting rules. — Los Angeles Times, 31 Aug. 2026 Speaker Mike Johnson, R-Louisiana, opposed the measure, calling it unconstitutional. — Swapna Venugopal Ramaswamy, USA Today, 31 Aug. 2026 Talwani again concluded that USPS likely lacked the authority to issue the rule and that the regulation was likely unconstitutional and contrary to law. — Kaelan Deese, The Washington Examiner, 31 Aug. 2026 The judge later ruled in late 2024 that the two sections were unconstitutional. — Joseph Flaherty, Arkansas Online, 28 Aug. 2026 See All Example Sentences for unconstitutional

Word History

First Known Use

1734, in the meaning defined above

Time Traveler
The first known use of unconstitutional was in 1734

Rhymes for unconstitutional

See All Rhymes for unconstitutional

Browse Nearby Words

unconstellated
unconstitutional
unconstrained
See all Nearby Words

Cite this Entry

“Unconstitutional.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unconstitutional. Accessed 4 Sep. 2026.

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Kids Definition

unconstitutional

adjective
un·​con·​sti·​tu·​tion·​al ˌən-ˌkän(t)-stə-ˈt(y)üsh-nəl How to pronounce unconstitutional (audio)
-ən-ᵊl
: not according to or agreeing with the constitution of a state or society
unconstitutionality
-ˌt(y)ü-shə-ˈnal-ət-ē How to pronounce unconstitutional (audio)
noun
unconstitutionally
-ˈt(y)üsh-nə-lē, 
-ən-ᵊl-ē
adverb

Legal Definition

unconstitutional

adjective
un·​con·​sti·​tu·​tion·​al ˌən-ˌkän-stə-ˈtü-shə-nəl, -ˈtyü- How to pronounce unconstitutional (audio)
: contrary to or failing to comply with a constitution
especially : violative of a person's rights guaranteed by the U.S. Constitution
an unconstitutional search and seizure
unconstitutionality
-ˌtü-shə-ˈna-lə-tē, -ˌtyü- How to pronounce unconstitutional (audio)
noun
unconstitutionally adverb

More from Merriam-Webster on unconstitutional

Thesaurus: All synonyms and antonyms for unconstitutional

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