Overly dull and feeble speech for a Wednesday say (7)
I believe the answer is:
midweek
'overly' is the definition.
Both the answer and definition are adverbs. Maybe you can see an association between them that I can't see?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for midweek that I've seen before include "Tuesday to Thursday?" , "Wednesday (or thereabouts)" , "Normal working day(s)" .)