Left in chests containing top sheets with flowers (8)
I believe the answer is:
blossoms
'left in chests' is the definition.
Although both the answer and definition are plural nouns, I can't see how they can define each other.
'top sheets with flowers' is the wordplay.
'top sheets' becomes 's' (I can't justify this - if you can you should believe this answer much more).
'with' says to put letters next to each other.
'flowers' becomes 'blossom' (I've seen this before).
's' put after 'blossom' is 'BLOSSOMS'.
'containing' acts as a link.
Can you help me to learn more?
(Other definitions for blossoms that I've seen before include "Puts forth flowers" , "Flowers, especially of fruit trees" , "Blooms" , "Develops nicely like flowers" , "Flourishes like flowers from fruit tree (8)" .)