perpetuity.

1. A state of lasting forever or continuing without an expected end.

2. An arrangement modeled as paying a fixed amount at regular intervals forever.

Use it for

Words that belong together

• in perpetuity
• held in perpetuity

On the page

The land was reserved in perpetuity, though no one had planned how it would be maintained.

Usage notes

Primary category: academic / formal. Forms: Usually uncountable for endless duration; financial arrangement singular perpetuity, plural perpetuities. Legacy lexical fields mirror sense 1 only. Use numbered sense fields for all meanings. Established modern English lexical item. No separate regional spelling or grammatical inflection entry. Writing functions: analysis, explanation. Commonness: moderately common.