unending
adj.having no end or lasting for a very long time. You use this to describe something that feels like it will never stop.
adj.having no end or continuing indefinitely. Often used to describe a state or process that feels exhausting or overwhelming due to its length.
“The long summer holidays felt like an unending period of time.”
“After working on the same project for three years without a break, the team felt like they were facing an unending challenge.”
“The philosopher argued that the pursuit of absolute truth is an unending journey, one that requires constant questioning and the rejection of any final, static conclusion.”
“His piece, his first use of lightbulbs, was made after the death of his partner Ross Laycock from an Aids-related illness and is about their unending love.”
From un- + ending.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.