Synonyms for Illegal (same or very similar meaning)
WordNet sense 1 (contrary to or forbidden by law):
illegitimate, illicit, unlawful
WordNet sense 2 (recently stolen or smuggled):
hot
WordNet sense 3 (involving or being or having the nature of a crime):
criminal, felonious
WordNet sense 4 (forbidden by law):
banned, prohibited
From the ODE community, based on WordNet
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