(1):

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

(2):

(n.) A perpetual annuity.

(3):

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

(4):

(n.) Something that is perpetual.

(5):

(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.

(6):

(n.) Duration without limitations as to time.

(7):

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

(8):

(n.) Endless time.