in perpetuum

adverb

in per·​pe·​tu·​um

-pə(r)ˈpechəwəm

: in perpetuity : forever

left certain royalties to the home in perpetuum

—Joseph Wechsberg

Word History

Etymology

Latin

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now