Second bag into which stuffed one work of art (6)
I believe the answer is:
mosaic
'work of art' is the definition.
(I've seen this before)
'second bag into which stuffed one' is the wordplay.
I cannot quite understand how this works, but
'second' could be 'mo' (both are short periods of time) and 'mo' is present in the answer.
'one' could be 'i' (Roman numeral) and 'i' is located in the answer.
'bag' could be 'sac' (a small bag) and 'sac' is present in the leftover letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for mosaic that I've seen before include "Picture made with pieces of glass and stone" , "Relating to Moses" , "Tessellated pattern" , "Design of small coloured squares" , "Picture made up of small pieces of coloured glass or stones" .)