OMG virtue! (8)
I believe the answer is:
goodness
'virtue' is the definition.
(I've seen this before)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for goodness that I've seen before include "Virtue; excellence" , "Exclamation of surprise" , "Virtue, rightness" , "Boy" , "merit" .)