Webster's Revised Unabridged Dictionary · 1913

Immune

Immune , adjective

[Latin immunis. See Immunity.]

1.
Exempt; protected.
2.
(Medicine) Protected from disease due to the action of the immune system, especially by having been inoculated against or previously exposed to a disease.
3.
(Medicine) Of or pertaining to the immune system or the components of the immune system.
4.
Not responsive; as, immune to suggestion.

Immune , noun

One who is immune; esp., a person who is immune from a disease by reason of previous affection with the disease or inoculation.