Mistake, performing as a shoe (4-2)
I believe the answer is:
slip-on
'a shoe' 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?
'mistake performing' is the wordplay.
'mistake' becomes 'slip' (a slip is a blunder or mistake).
'performing' becomes 'on' (as in being on stage).
'slip'+'on'='SLIP-ON'
'as' acts as a link.
Can you help me to learn more?
(Other definitions for slip-on that I've seen before include "Not a lace-up" , "Shoe without fasteners" , "Shoe without laces" , "Without fastening" , "Garment or shoe with little or no fastening" .)