impermissible

adjective

im·​per·​mis·​si·​ble ˌim-pər-ˈmi-sə-bəl 

: not permissible

impermissibility

ˌim-pər-ˌmi-sə-ˈbi-lə-tē 

noun

impermissibly

ˌim-pər-ˈmi-sə-blē 

adverb

Synonyms of impermissible

• prohibited
• forbidden

Examples of impermissible in a Sentence

Such behavior is impermissible under the new guidelines.

an impermissible breach of etiquette

Recent Examples on the Web

In 2025, the Colorado Supreme Court rejected the companies’ argument, holding that the lawsuit is a valid legal challenge regarding public deception and local costs, rather than an impermissible attempt to regulate federal emissions. — Patrick Parenteau, The Conversation, 30 Sep. 2026

The league penalized Frank for his involvement with the impermissible endorsement arrangements and for approving impermissible expenses incurred by Leonard and his family. — ABC News, 2 Sep. 2026

Clippers President of Basketball Operations Lawrence Frank is suspended without pay for six months for his involvement with the impermissible endorsement arrangements and for approving impermissible expenses incurred by Leonard and his family. — Jason Anderson, Sacbee.com, 2 Sep. 2026

The first involved an impermissible contact with the family of a prospective recruit at a restaurant in 2019, which the NCAA’s complex case unit classified as a Level II violation. — Daniel Libit, Sportico.com, 25 Aug. 2026

Word History

First Known Use

1829, in the meaning defined above

Rhymes for impermissible

• admissible
• immiscible
• permissible
• transmissible
• inadmissible
• indivisible
• inexplicable
• miscible

Kids Definition

impermissible

adjective

im·​per·​mis·​si·​ble ˌim-pər-ˈmis-ə-bəl 

: not permissible

impermissibility

-ˌmis-ə-ˈbil-ət-ē 

noun

impermissibly

-ˈmis-ə-blē 

adverb

Legal Definition

impermissible

adjective

im·​per·​mis·​si·​ble ˌim-pər-ˈmi-sə-bəl 

: not permissible

impermissibly adverb