eternity

As nouns the difference between eternity and timelessness

is that eternity is existence without end, infinite time while timelessness is the property of being timeless.

As nouns the difference between eternity and future

is that eternity is existence without end, infinite time while future is the time ahead; those moments yet to be experienced.

As an adjective future is

having to do with or occurring in the future.

As nouns the difference between eternity and null

is that eternity is (uncountable) existence without end, infinite time while null is zero, nil; the cardinal number before einn.

As nouns the difference between immortal and eternity

is that immortal is one who is not susceptible to death while eternity is (uncountable) existence without end, infinite time.

As an adjective immortal

is not susceptible to death; living forever; never dying.

As an adjective perpetual

is lasting forever, or for an indefinitely long time.

As a noun eternity is

existence without end, infinite time.

As a noun eternity

is (uncountable) existence without end, infinite time.

As an adjective timeless is

eternal.

As nouns the difference between now and eternity

is that now is new moon while eternity is (uncountable) existence without end, infinite time.

As a noun eternity

is (uncountable) existence without end, infinite time.

As an adverb ever is

always.

As an adjective ever is

(epidemiology) occurring at any time, occurring even but once during a timespan.

As nouns the difference between everlasting and eternity

is that everlasting is an everlasting flower while eternity is existence without end, infinite time.

As an adjective everlasting

is lasting or enduring forever; existing or continuing without end; immortal; eternal.

As nouns the difference between eternity and permanent

is that eternity is (uncountable) existence without end, infinite time while permanent is a chemical hair treatment imparting or removing curliness, whose effects typically last for a period of weeks; a perm.

As an adjective permanent is

without end, eternal.

As a verb permanent is

(dated) to perm (the hair).