interminable

Synonyms: boring boundless ceaseless constant continuous day-and-night dragged out dull endless eternal everlasting immeasurable incessant interminate limitless long long-drawn-out long-winded looped never-ending no end of no end to on a treadmill permanent perpetual protracted spun out strung out timeless unbound unceasing uninterrupted unlimited wearisome

Antonyms: bounded ending finite terminable