DNA strand altered, erasing a bit of narcissistic quality (8)
I believe the answer is:
standard
'quality' is the definition.
(standard is a kind of quality)
'dna strand altered erasing a bit of narcissistic' is the wordplay.
I cannot quite understand how this works, but
an anagram of 'dna' is 'and' which is present in the answer.
'a' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for standard that I've seen before include "Ordinary Level?" , "The usual range" , "Accepted model - flag" , "Military flag" , "Principle" .)