illegal Meaning, Definition & Usage

  1. adjective prohibited by law or by official or accepted rules
    • an illegal chess move

WordNet

Il*le"gal adjective
Etymology
Pref. il- not + legal: cf. F. illégal.
Definitions
  1. Not according to, or authorized by, law; specif., contrary to, or in violation of, human law; unlawful; illicit; hence, immoral; as, an illegal act; illegal trade; illegal love. Bp. Burnet.

Webster 1913