Tired little dog eating article up (5)
I believe the answer is:
banal
'tired' is the definition.
(both can mean boring)
'little dog eating article up' is the wordplay.
'little dog' becomes 'lab' (short for Labrador).
'eating' indicates putting letters inside.
'article' becomes 'an' (indefinite article).
'up' is a reversal indicator (in down clue: letters go upwards).
'lab' going around 'an' is 'lanab'.
'lanab' in reverse letter order is 'BANAL'.
(Other definitions for banal that I've seen before include "'Hackneyed, trite (5)'" , "Stock" , "tired" , "Tediously commonplace" , "Overfamiliar through overuse" .)