Frustrate British brilliance (6)
I believe the answer is:
blight
This clue might be a double definition.
'frustrate' is the first definition.
(I've seen this in another clue)
'british brilliance' is the second definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
Can you help me to learn more?
(Other definitions for blight that I've seen before include "Problem of plants or urban development" , "Plant disease; urban eyesore" , "Withering disease (in plants)" , "Potato disease" , "Disease or fungus that withers plants, say potatoes" .)