Dull, lacking inspiration (10)
I believe the answer is:
pedestrian
I believe this clue is a double definition.
'dull' is the first definition.
(similar in meaning)
'lacking inspiration' is the second definition.
(I've seen this before)
(Other definitions for pedestrian that I've seen before include "A person travelling on foot" , "Unexciting" , "flat" , "Run-of-the mill" , "not very fast" .)