Tediously unoriginal (5)
I believe the answer is:
banal
'tediously unoriginal' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for banal that I've seen before include "Boring or trivial" , "Trite or fatuous" , "Stock" , "Ordinary and uninteresting" , "'Hackneyed, trite (5)'" .)