Cover up bucket and regularly ruin collection (9)
I believe the answer is:
potpourri
'collection' is the definition.
(I know that potpourri is a type of collection)
'cover up bucket and regularly ruin' is the wordplay.
I cannot really see how this works, but
'bucket' could be 'pour' (I've seen this before) and 'pour' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for potpourri that I've seen before include "leaves, petals etc." , "Selection" , "Hotchpotch" , "miscellaneous stuff" , "Perfumed mixture; medley" .)