You searched for: “aere perennius
aere perennius (Latin phrase)
Literally, copper or bronze through the year; and by extension: durable, lasting: In the Bronze Age, aere perennius metal represented permanence, since bronze tools were so much less brittle than the stone implements of earlier times.

When a Roman spoke of something as being aere perennius, or "more durable than bronze", he meant that it would last forever.

Word Entries at Get Words containing the term: “aere perennius
Menumentum aere perennius.
A monument more lasting than brass.
This entry is located in the following unit: Graveyard words for a greater understanding of epitaphs (page 5)