Sempiternal:
- everlasting; eternal. [Dictionary.com]
Reader (and occasional contributor) Chris Johnson noted it in “The Last Hours of El Faro: An excerpt from RUN THE STORM,” George Michelson Foy, Soundings:
The ongoing pulse of engines deep below, the sempiternal tremble of deck and joinery that is the sign, tactile as much as auditory, that El Faro’s heart is beating, her engines driving her and all her people in the direction they’re supposed to go in, begins to falter.
Slows in rhythm.
Fades, at last, to nothing.
Perhaps not quite used properly, at least according to the definition I found.