The most common and most likely answer to this crossword clue is the 8 letter word SURVIVAL
S
U
R
V
I
V
A
L
Buddy explains!
The straight part
We know that "relic" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case relic = survival.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SURVIVAL mean?
SURVIVAL noun- The fact or act of surviving; continued existence or life.
- (as a modifier) Of, relating to or aiding survival.
- The avoidance of relegation or demotion to a lower league or division.
- A custom or belief that persists in folklore from earlier times, when the rationale behind it is forgotten.