everlasting
adj.lasting forever or for a very long time. You use it to describe things that never seem to end, like love or a long wait.
adj.lasting forever or for an indefinitely long period. Often carries a poetic or religious tone when describing abstract concepts like life or truth.
“They promised each other everlasting love.”
“The philosopher argued that the search for everlasting truth is what defines the human experience.”
“The poet sought to capture the everlasting beauty of the landscape, hoping his verses would remain relevant long after the physical world had changed.”
Typically used attributively before the noun it modifies.
From Middle English ever-lasting (“(adjective) eternal, perpetual; constant; (adverb) eternally; (noun) eternity”), from ever (“at all times, always, constantly; eternally, perpetually; regularly; etc.”) + lasting (“continuing, lasting; eternal; etc.”). Ever is derived from Old English ǣfre (“ever”), possibly from ā (“always, ever”) + in fēore (“in life”). Ā is from Proto-West Germanic aiw (“eternity; long time”), from Proto-Germanic aiwaz (“long time; eternity”), ultimately from Proto-Indo-European h₂ey- (“life, vital force; long time; eternity”); and fēore is the dative singular of feorh (“life”), from Proto-West Germanic ferh (“life; kind of tree”), from Proto-Germanic ferhwą (“body; life; tree”), probably ultimately from Proto-Indo-European *perkʷ- (“oak tree”) (as the oak represented life and vitality in Germanic mythology). Lasting is derived from lasten (“to continue, last; etc.”) + -ing (suffix forming present participle forms of verbs, often used as adjectives)); and lasten from Old English lǣstan (“to follow, pursue; to carry out, perform”), from Proto-West Germanic laistijan (“to follow, pursue; to carry out, perform”), from Proto-Germanic laistijaną (“to follow, pursue”), ultimately from Proto-Indo-European leys- (“to trace, track”). By surface analysis, ever (adverb) + lasting (adjective).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.