Scorn letters with a repetitiveness about them (6)
I believe the answer is:
deride
'scorn' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for deride that I've seen before include "Speak of with contempt" , "Mock and jeer" , "Jeer, belittle" , "Test performance" , "Ridicule, scoff at" .)