infamous āļāļ·āļāļāļ°āđāļĢ infamous āļāļ·āļāļāļ°āđāļĢ Having an exceedingly bad reputation; notorious.Causing or deserving infamy; heinous: an infamous deed. Law Punishable by severe measures, such as death, long imprisonment, or loss of civil rights.Law Convicted of a crime, such as treason or felony, that carries such a punishment.