endless

Immortalinterminable is a related term of endless.

As an adjective endless is

having no end.

Endless is a related term of incorruptible.

As adjectives the difference between endless and incorruptible

is that endless is having no end while incorruptible is not subject to corruption or decay.

As a noun incorruptible is

(historical) one of an ancient religious sect of alexandria, whose adherents believed that the body of christ was incorruptible, and that he suffered hunger, thirst, and pain only in appearance.

As adjectives the difference between endless and permanent

is that endless is having no end while permanent is without end, eternal.

As a noun permanent is

a chemical hair treatment imparting or removing curliness, whose effects typically last for a period of weeks; a perm.

As a verb permanent is

(dated) to perm (the hair).

Never-ending is a synonym of endless.

As adjectives the difference between endless and never-ending

is that endless is having no end while never-ending is alternative form of lang=en.

Incalculable is a related term of endless.

As adjectives the difference between incalculable and endless

is that incalculable is (not comparable) very great or numerous while endless is having no end.

As adjectives the difference between untold and endless

is that untold is not told; not related; not revealed while endless is having no end.

As adjectives the difference between endless and deep

is that endless is having no end while deep is Extending far away from a point of reference, especially downwards.

As an adverb deep is

deeply.

As a noun deep is

the deep part of a lake, sea, etc.