1. (n.) The quality or state of being perpetual; as, the perpetuity of laws.

2. (n.) Something that is perpetual.

3. (n.) Endless time.

4. (n.) The number of years in which the simple interest of any sum becomes equal to the principal.

5. (n.) The number of years' purchase to be given for an annuity to continue forever.

6. (n.) A perpetual annuity.

7. (n.) Duration without limitations as to time.

8. (n.) The quality or condition of an estate by which it becomes inalienable, either perpetually or for a very long period; also, the estate itself so modified or perpetuated.

abidingness age all-comprehensiveness all-inclusiveness antiquity boundlessness ceaselessness chattering constancy constant flow continualness continuance continuity countlessness defeat of time defiance of time distance diuturnity durability durableness duration endlessness endurance eternity exhaustlessness extension extent forever illimitability immeasurability immensity incalculability incessancy incomprehensibility inexhaustibility infiniteness infinitude infinity innumerability interminability lastingness length lengthiness limitlessness linear measures long standing long time long-lastingness long-livedness longevity longitude longness maintenance measure measurelessness mileage noninterruption numberlessness oscillation overall length perdurability perennation permanence persistence pulsation quick fire rapid fire rapid recurrence rapid succession rapidity reach regularity repetition span stability staccato standing steadfastness steadiness stretch stuttering survival survivance sustainment tattoo termlessness timelessness unintermission uninterruption universality unmeasurability vibration world without end yardage