Item of footwear that is in good condition swapped (6)
I believe the answer is:
wellie
'item of footwear' is the definition.
'wellie' can be an answer for 'footwear' (I've seen this before). I am not certain of the 'item of' bit.
'that is in good condition swapped' is the wordplay.
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'in good condition' becomes 'well' (I've seen this before).
'swapped' means one lot of letters go next to another.
'ie' after 'well' is 'WELLIE'.
Can you help me to learn more?
(Other definitions for wellie that I've seen before include "Greek letter" , "Waterproof boot" , "footwear" , "energy" , "In the countryside, it may be green" .)