Untouchable
Part of speech: noun
Definition: A criminal so adept, they cannot be arrested (effective bribes securely in place.) A pariah. (Dated) In the Indian caste system, a member of the lowest caste. An incorruptible law enforcement agent
Part of speech: adjective
Definition: Not able to be touched.
Example sentence: Serbia has become a pariah nation, untouchable like a leper.
Invulnerable
Part of speech: adjective
Definition: Incapable of being wounded, or of receiving injury; not vulnerable.Unanswerable; irrefutable; unable to be damaged by an attack or convinced; as, an invulnerable argument.