If you describe something as interminable, you are emphasizing that it continues for a very long time and indicating that you wish it was shorter or would stop.

What does a interminable mean?

: having or seeming to have no end especially : wearisomely protracted an interminable sermon.

What word means the same as interminable?

boundless, continuous, endless, eternal, incessant, limitless, long-winded, never-ending, perpetual, protracted, boring, ceaseless, constant, day-and-night, dull, everlasting, immeasurable, long, long-drawn-out, looped.