Synonyms for Endless:

adj.

ageless (adjective)
dateless.
all (adjective)
eternal, interminable.
continuing (adjective)
unending.
continuous (adjective)
flat, unbroken, level, recurrent, regular, seamless, straight, unchanging, even, indefatigable, habitual, repetitive, persistent, constant, nonstop, steady, unvarying, un-intermittent, lasting, perpetual, robot-like, invariable, sequential, everlasting, consecutive, consistent, gapless, connected, undeviating, featureless, unremitting, undying, continual, incessant, continuous, unending, continuing, monotonous, cyclical, unchangeable, monolithic, coherent, ceaseless, repeated, uniform, interminable, homogeneous, unceasing, perennial.
infinite (adjective)
illimitable, ceaseless, boundless, countless, unbounded, everlasting, immeasurable, eternal, unlimited, perpetual, inexhaustible, immemorial, timeless, innumerable, limitless, incalculable, bottomless, numberless, interminable, infinite, Termless.
never-ending (adjective)
ceaseless.
not stopping, not finishing (adjective)
enduring, unsurpassable, unending, amaranthine, continual, everlasting, immortal, infinite, continuous, immeasurable, undying, incessant, unlimited, multitudinous, untold, illimitable, uninterrupted, boundless, unbounded, eternal, numberless, constant, limitless, monotonous, incalculable, interminable, countless, perpetual, unbroken, measureless, ceaseless.
perpetual (adjective)
uninterrupted, infinite, continual, ceaseless, eternal, enduring, incessant, permanent, immortal, everlasting, unceasing, lasting, constant, interminable.
wordy (adjective)
featherbedding, excessive, rambling, loquacious, long-winded, grandiloquent, superfluous, lengthy, talkative, wordy, bombastic, chatty, wandering, ponderous, verbose, windy.

n.

continue, world without end, amaranthine, Eterne. relentless, round the clock, ongoing, around the clock. endless (noun)
dateless, incessant, sempiternal, continual, infinite, uninterrupted, eternal, long, perpetual, continuous, interminable.

Other synonyms:

unconditional, unrestricted, world without end, round the clock, unregulated, forever, around the clock, uncontrolled, amaranthine. ongoing, Eterne. relentless. bottomless
measureless.
sempiternal
sempiternal.

Usage examples for endless

  1. Certainly that was not the method to obtain an endless existence, but it was the true preparation for receiving spiritual good. – Orthodoxy: Its Truths And Errors by James Freeman Clarke
  2. And when the time comes for endless dreams.... – The Gay Cockade by Temple Bailey
  3. The girl was an endless source of amusement to the skipper and the crew. – Literary Lapses by Stephen Leacock