Definition of "sempiternal"
Everlasting, eternal.
Quotations
The one thing which we seek with insatiable desire is to forget ourselves, to be surprised out of our propriety, to lose our sempiternal memory, and to do something without knowing how or why; in short, to draw a new circle. Nothing great was ever achieved without enthusiasm.
1841, R[alph] W[aldo] Emerson, “Essay X. Circles.”, in Essays, Boston, Mass.: James Munroe and Company, page 265