Adjective lawful has 4 senses
  1. lawful - conformable to or allowed by law; "lawful methods of dissent"
    unlawful, outlaw, open, wide-open, lawless, wrongful
  2. lawful, orderly, rule-governed - according to custom or rule or natural law
    Antonym: irregular (indirect, via regular)
  3. true, lawful, rightful - having a legally established claim; "the legitimate heir"; "the true and lawful king"
    Antonym: illegitimate (indirect, via legitimate)
  4. lawful, legitimate, licit - authorized, sanctioned by, or in accordance with law; "a legitimate government"
    Antonym: illegal (indirect, via legal)