A lady's ring, worn on the hand, comprising a band of precious metal (usually gold) set with a continuous line of identically cut gemstones (usually diamonds) to symbolize never-ending love, usually given by a husband to his wife on a significant anniversary.

plural of eternity ring

plural of eternity collar

A collar worn by a BDSM submissive as a sign of devotion and never taken off

(cosmology, religion, philosophy) Eternal recurrence.

(cosmology, religion, philosophy) The belief or theory that all the events in cosmic history repeat in an endless cycle.

Immortality. / (religion) Life after death; the afterlife.

(religion, philosophy, psychology) The condition in which all reality is experienced in the present, with the past contained only in memory and the future only in anticipation or speculation.

(idiomatic) A relationship involving three persons (usually two women and one man or two men and one woman) among whom there are conflicting and competing attachments of a romantic or emotional nature.

(Internet slang, historical) A period beginning around 1993, in which large amounts of new users were joining Usenet.