Bag short suit (9)
I believe the answer is:
briefcase
'bag' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'short suit' is the wordplay.
'short' becomes 'brief' (synonyms).
'suit' becomes 'case' (synonyms).
'brief'+'case'='BRIEFCASE'
Can you help me to learn more?
(Other definitions for briefcase that I've seen before include "Carried by lawyer" , "Carrying container for files" , "See fabric covering container for business papers" , "Container for carrying papers" , "One transfers papers" .)