unauthorized

unauthorized — adjective

1. not having official permission from a person or organization with the right to a

1.adjectiveB2
Definition

not having official permission from a person or organization with the right to allow it

Example

Mayumi made an unauthorized entry into the office building after hours.

collocation: unauthorized entry

The company policy states that employees must not install unauthorized software on work computers.

collocation: unauthorized software — company rules context

Common collocations
  • unauthorized access
  • unauthorized use
  • unauthorized entry
  • unauthorized transaction
  • unauthorized software
Synonyms
  • unapproved

    more specific — suggests a request was reviewed and rejected, while unauthorized means permission was never sought

  • illegal

    stronger — implies a law has been broken, not just a rule or policy

  • unlicensed

    narrower — specifically about lacking a license or certificate

Antonyms
  • authorized

    the direct opposite — having official permission

  • permitted

    milder — allowed, though not necessarily through a formal process

Grammar Patterns

unauthorized + noun

be + unauthorized

Usage Note

Commonly used before a noun (attributive) in legal, security, and financial contexts. Can also follow a linking verb: 'This transaction was unauthorized.'

Common Mistakes

He did an unauthorized thing.
He made an unauthorized change to the contract.
'unauthorized' is typically paired with a specific noun (access, use, entry, transaction), not a general word like 'thing'.

Word family

  • authorize
    verbB2
  • authorization
    nounB2
  • authorized
    adjectiveB2
  • unauthorised
    adjectiveB2

Synonym discussion

Sense: adjective/1

Unauthorized, unapproved, illegal, and unlicensed all describe something that is not allowed, but they differ in scope and severity. Unauthorized is the broadest term — it simply means official permission was not given, whether or not anyone asked for it. Unapproved is narrower: it implies someone did ask but was told no, so the rejection is known. Illegal is the strongest — the action breaks a law and can result in criminal punishment, not just a policy violation. Unlicensed is the most specific — it means the person or thing lacks a required license or certificate, such as a driving license or a business permit. For example, parking in a restricted zone is unauthorized; parking where the sign clearly says "No Parking" and you saw it is still unauthorized but not necessarily illegal (it may be a civil fine). If you park without a valid driver's license, that is unlicensed driving. If you park in a spot reserved for disabled drivers without a permit, that may be illegal.

unauthorized ↗unapprovedillegal ↗unlicensed

Common collocations

Nouns

Adverbs

  • clearly unauthorized
  • highly unauthorized
  • strictly unauthorized

Phrases

  • unauthorized by law
  • unauthorized by management

Prepositions

  • unauthorized by

Etymology

LatinMedieval LatinFrenchEnglish

Formed in English by adding the prefix 'un-' (meaning 'not') to 'authorized', the past participle of 'authorize'. 'Authorize' traces back through Medieval Latin 'auctorizare' to Latin 'auctor', meaning 'originator, promoter, or creator'. The modern sense of official permission emerged in legal and administrative English during the 1600s.