unconstitutional

adjective

un·​con·​sti·​tu·​tion·​al ˌən-ˌkän(t)-stə-ˈtü-sh(ə-)nəl 

-ˈtyü-

: 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 

-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

The state constitution requires at least four of the five justices to agree for a law to be found unconstitutional, a high bar. —CBS News, 22 Nov. 2025

In March, the Supreme Court of Louisiana rejected an attempt to declare the state's immunity law unconstitutional from a woman who developed pressure ulcers during a lengthy rehab hospital stay in early 2020. —Madeline Heim, jsonline.com, 21 Nov. 2025

The Supreme Court could also render his tariffs moot if they’re struck down as unconstitutional without approval from Congress in a pending case before the high court. —Ramsey Touchberry, The Washington Examiner, 21 Nov. 2025

That lawsuit is pending in federal court, and challenges the waivers as an unconstitutional delegation of congressional authority. —Brandon Loomis, AZCentral.com, 18 Nov. 2025

Word History

First Known Use

1734, in the meaning defined above

Rhymes for unconstitutional

• noninstitutional
• attributional
• constitutional
• convolutional
• distributional
• institutional
• involutional
• substitutional
• interinstitutional

Kids Definition

unconstitutional

adjective

un·​con·​sti·​tu·​tion·​al ˌən-ˌkän(t)-stə-ˈt(y)üsh-nəl 

-ən-ᵊl

: not according to or agreeing with the constitution of a state or society

unconstitutionality

-ˌt(y)ü-shə-ˈnal-ət-ē 

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- 

: 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- 

noun

unconstitutionally adverb