illicit vs. illegal

illicit

adjective

  1. not legally permitted or authorized; unlicensed; unlawful.

    Synonyms: prohibited, illegitimate

  2. disapproved of or not permitted for moral or ethical reasons.

illegal

adjective

  1. forbidden by law or statute.

    Synonyms: unlicensed, illicit, illegitimate, unlawful

  2. contrary to or forbidden by official rules, regulations, etc..

    The referee ruled that it was an illegal forward pass.

noun

  1. Informal: Disparaging and Offensive.,  illegal alien.