Find Synonyms

illegal Synonyms

Another word for illegal

Choosing another word for illegal depends on context, so the 18 synonyms and similar words below are separated across 3 exact definitions and ranked by match strength.
JUMP TO:

• adjective (Context 1)

Contrary to or forbidden by law, especially criminal or statutory law.

Usage Example

"It is unlawful to drive a motor vehicle without a valid license."

Strongest
unlawful
illicit
Strong
prohibited
forbidden
illegitimate
criminal
banned
outlawed
felonious
contraband

• adjective (Context 2)

Not permitted by the official rules of a sport, game, or computing system.

Usage Example

"The referee penalized the defender for making an invalid tackle near the goal line."

Strongest
invalid
Strong
unauthorized
prohibited
foul
unpermitted

• noun (Context 3)

An intelligence operative who lives and works under a false identity in a foreign country without diplomatic cover or official protection.

Usage Example

"During the Cold War, the intelligence agency trained deep-cover illegals to blend seamlessly into foreign communities."

Strong
spy
sleeper
operative
secret agent

Opposites of illegal

The opposite of illegal shifts depending on context. Common opposites include:

legal
lawful
valid
legitimate
licit
allowed
permissible
citizen
See all opposites of illegal

• Nearby Words

ilk
ill
illadopsis
illegal
illegality
illegalization
illegalize

Cite this Entry

Wordmom. (2026). Synonyms for Illegal. In Wordmom Thesaurus. Retrieved Nov 5, 2026, from https://wordmom.com/synonyms/illegal
Built for writers, students, and competitive word game players, Wordmom combines an uncluttered English dictionary and thesaurus with fast, pattern-based word finders so you can verify definitions, synonyms, and high-scoring tile plays in one place.
Word Games & Solvers
Word FinderScrabble Word FinderWords With Friends CheatWordle SolverAnagram Solver
Dictionary & Reference
DictionarySynonymsAntonymsWords
Community
Contact UsEditorial PolicyPrivacy PolicyTerms and Conditions
© 2016–2026 Wordmom Network. All rights reserved. Made with for word lovers everywhere.
Disclaimer: SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A. and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro. Words With Friends® is a registered trademark of Zynga Inc. Wordle® is a registered trademark of The New York Times Company. Other referenced game titles and tournament lexicon codes (including NASPA NWL and WESPA/HarperCollins CSW) are trademarks of their respective owners. Wordmom is an independent reference utility for educational and entertainment purposes and is not affiliated with, sponsored by, or endorsed by Hasbro, Mattel, Spear, Zynga, The New York Times Company, NASPA, WESPA, or HarperCollins Publishers. All game names are referenced strictly under nominative fair use to indicate compatibility.