Invent importance for unimportant addition (10)
I believe the answer is:
makeweight
'unimportant addition' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'invent importance' is the wordplay.
'invent' becomes 'make' (I can't justify this - if you can you should give a lot more credence to this answer).
'importance' becomes 'weight' (weight is a kind of importance).
'make'+'weight'='MAKEWEIGHT'
'for' is the link.
Can you help me to learn more?
(Other definitions for makeweight that I've seen before include "Small addition to make up mass" , "Small thing added to make up batch" , "deficiency" , "Unimportant addition to complete something" , "It helps the balance" .)