All 3 Uses of

immortal
in
The Hunchback of Notre Dame

Now, what a precarious immortality is that of the manuscript!†
Chpt 1.5.2 *

immortality = eternal life (to live forever)

to love with all the fury of one's soul; to feel that one would give for the least of her smiles, one's blood, one's vitals, one's fame, one's salvation, one's immortality and eternity, this life and the other; to regret that one is not a king, emperor, archangel, God, in order that one might place a greater slave beneath her feet; to clasp her night and day in one's dreams and one's thoughts, and to behold her in love with the trappings of a soldier and to have nothing to offer her but a priest's dirty cassock, which will inspire her with fear and disgust!†
Chpt 2.8.4

Definitions:

(1) (immortal)
living or existing forever

or:

someone famous throughout history

or:

someone who will never die -- such as a mythological god
(2) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

More rarely, "The Immortals" denotes a military corps of the Persian Empire. The Immortals were so-named because each time a member of the 10,000 man corps was killed or seriously wounded, he was replaced by another man. They are best remembered in western culture for their role in defeating the badly out-numbered Spartans at the Battle of Thermopylae.