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

Millions of tax dollars will be spent in court defending something that is obviously unconstitutional. — Sun Sentinel Editorial Board, Sun Sentinel, 9 July 2026

In April 2018, Trinidad’s High Court found the laws unconstitutional, but a local appeals court partially reversed that ruling in March 2025. — ABC News, 8 July 2026

The latest decision came in two lawsuits brought by professors, students and a student group who argued the law amounted to unconstitutional classroom censorship. — Luke Fountain, CNBC, 7 July 2026

And with the final decision of its term, the court ruled that his executive order reinterpreting birthright citizenship was unconstitutional. — Henry Gass, Christian Science Monitor, 7 July 2026

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