relic

Short definition from Wiktionary

Noun

1. 1
   That which remains; that which is left after loss or decay; a remaining portion.
2. 2
   Something old and outdated, possibly kept for sentimental reasons.
3. 3
   A part of the body of a saint, or an ancient religious object, kept for veneration.
4. 4
   A particle or entity that has existed since the Big Bang.

Verb

1. 1
   To cause (an object) to appear old or worn, to distress.

Adjective

1. 1
   Pertaining to the Big Bang.