imperishable, ageless, never-failing, forever, without end, unfailing, eonian, unfading, indefinite, enduring, dateless, never-ending, live, fadeless, deathless, permanent, continue, immortal, eternal, ever-living, ongoing, timeless
continuous (part of speech: adjective)
flat, constant, level, seamless, perennial, cyclical, unremitting, incessant, consistent, ceaseless, coherent, unchanging, indefatigable, recurrent, habitual, everlasting, interminable, invariable, uniform, consecutive, continuous, monolithic, repetitive, persistent, endless, unchangeable, unceasing, homogeneous, undeviating, steady, unvarying, featureless, monotonous, sequential, even, perpetual, unending, continual, unbroken, regular, nonstop, lasting, connected, repeated, un-intermittent, gapless, straight, continuing, robot-like
- He had come to pay his respects to me, he said, to declare his undying gratitude to Madame Garnet, and to bid me farewell. - "Youth and the Bright Medusa", Willa Cather.
- According to this explanation, the sorrowful expression of Antinous must indicate the agony of death through which he passed into the company of the undying. - "Sketches and Studies in Italy and Greece, Vol III.", John Symonds.
- Their anger on account of the humiliation of a woman was quickly forgotten; thoughts of coming battles, undying renown and conqueror's laurels to be won by deeds of arms, and recollections of their former mighty deeds raised the spirits of the revellers. - "The Complete Historical Romances of Georg Ebers", Georg Ebers.