Inapt sort of emulsion (5)
I believe the answer is:
paint
'emulsion' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'inapt sort' is the wordplay.
'sort' indicates an anagram.
'inapt' is an anagram of 'PAINT'.
'of' is the link.
Can you help me to learn more?
(Other definitions for paint that I've seen before include "Artist's material" , "A pint of liquid decoration" , "Eg, emulsion or gloss" , "Item used by 23 Across" , "Daub" .)