All 4 Uses of

immortal
in
Atlas Shrugged

The words and the voice had the genuine simplicity of truth, "Dr. Akston, I ....it's inconceivable, it's ....You're ....you're a philosopher ....the greatest philosopher living ....an immortal name ....why would you do this?"†
Chpt 1.10 *

But the work of building a path was a living sum, so that no day was left to die behind her, but each day contained all those that preceded it, each day acquired its immortality on every succeeding tomorrow.†
Chpt 2.8

immortality = eternal life (to live forever)

It was John whom he regarded as his particular heir, as his future, as his own immortality.†
Chpt 3.2

If they pursue it, they will not achieve a market, a fortune or an immortal famethey will merely destroy production, employment and art.†
Chpt 3.2

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.