illicit

Adjective

• contrary to or forbidden by law
  • an illegitimate seizure of power
    
  • illicit trade
    
  • an outlaw strike
    
  • unlawful measures
    

• contrary to accepted morality (especially sexual morality) or convention
  • an illicit association with his secretary
    

Related words

• Synonyms: 
  illegitimate , outlaw(a) , outlawed , unlawful