unauthorized

adjective

Definition of unauthorizednext
as in improper
without permission; not authorized an unauthorized use of government vehicles Unauthorized personnel are not allowed in the building.

Related Words

Relevance

Dissimilar Words

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 unauthorized The 2-1 decision rejected Anthropic's argument that the Department of Defense's ban on its Claude models was arbitrary, unauthorized and unconstitutional. — Lora Kolodny, CNBC, 13 Oct. 2026 Cybersecurity protects systems against unauthorized access and manipulation, while functional safety protects people, equipment and the environment when systems fail or behave incorrectly. — Gregory Shahnovsky, Forbes.com, 13 Oct. 2026 In all, some 700 agents found a way to communicate, using an unauthorized message board, and coordinate an attack on the computer systems of fellow AI company Hugging Face. — Laurent Belsie, Christian Science Monitor, 13 Oct. 2026 Microsoft tells CyberGuy that two unauthorized posts appeared during the period when its account was compromised. — Kurt Knutsson, FOXNews.com, 11 Oct. 2026 See All Example Sentences for unauthorized
Recent Examples of Synonyms for unauthorized
  1. improper
  2. illicit
  3. unlawful
  4. inappropriate
  5. unacceptable
  6. illegitimate
Adjective
  • In 2024, its football program acknowledged impermissible recruiting contacts during the COVID-19 recruiting dead period, improper tryouts and unauthorized coaching by noncoaching staff.
    — Jackson Thompson OutKick, FOXNews.com, 11 Oct. 2026
  • The production was shut down in Livingston, Montana last Saturday when locals complained about the production’s impact on the Livingston food bank and improper warnings about hazardous stunts.
    — Pat Saperstein, Variety, 10 Oct. 2026
Definition of improper
Adjective
  • The group’s president and CEO, Steve Lamar, said the AAFA is urging stronger action against platforms that enable the trade of dupes and fakes, which can be dangerous to consumers as the illicit goods are produced through unregulated operations.
    — Kate Nishimura, Footwear News, 9 Oct. 2026
  • Both local and federal investigators are investigating the source and supplier of the illicit drugs.
    — ABC News, ABC News, 9 Oct. 2026
Definition of illicit
Adjective
  • The next year Williams was charged in the Southern District of Iowa for unlawful flight to avoid prosecution in the kidnapping case.
    — Breaking News, Los Angeles Times, 10 Oct. 2026
  • Federal authorities later charged him with unlawful flight to avoid prosecution.
    — Greg Wehner, FOXNews.com, 9 Oct. 2026
Definition of unlawful
Adjective
  • On the police's Facebook account on Tuesday, officers criticized inappropriate comments and warned that sharing or joking about such incidents can worsen the impact on any victim.
    — ABC News, ABC News, 13 Oct. 2026
  • In addition, pharmaceutical advertising or education aimed at doctors may also increase inappropriate prescribing, probably increases the number of prescriptions written, and may increase the costs of prescriptions.
    — Ed Silverman, STAT, 9 Oct. 2026
Definition of inappropriate
Adjective
  • The idea of not spending evenings with my kid is, kids are, is completely unacceptable.
    — Michael Birnbaum The Washington Post, Arkansas Online, 14 Oct. 2026
  • OpenAI took months to discover the incident and notify the Australian agencies affected — that’s unacceptable by my standard.
    — Rumman Chowdhury, Vogue, 13 Oct. 2026
Definition of unacceptable
Adjective
  • An adult child can claim authority over the meaning of a life without proving that everything inherited is therefore illegitimate.
    — Literary Hub, Literary Hub, 9 Oct. 2026
  • Saman admitted to purchasing much of his inventory from brokers or middlemen, which the department identified as illegitimate distributors of the brands.
    — Glenn Taylor, Footwear News, 8 Oct. 2026
Definition of illegitimate

Browse Nearby Words

unauthentic
unauthorized
unavailability
See all Nearby Words

Cite this Entry

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

Copy Citation
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Last Updated: - Updated example sentences

Popular in Grammar & Usage

See More

'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'?
See More

Popular in Wordplay

See More

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. 9
See More

Popular

See More

'Affect' vs. 'Effect'

16 Food Words Recently Added to the Dictionary

The Real Origin of 'Supercalifragilistic'
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
a cup of tea and a golf ball on tee side by side
Quiz: Sounds Like... Choose the word that sounds like it fits the clue...
See All