This can be hot and cold when picked up (6)
I believe the answer is:
chilli
'this can be hot' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'cold when picked up' is the wordplay.
'cold' becomes 'chilly' (I've seen this before).
'when picked up' shows a homophone (sound like).
'chilly' is a homophone of 'CHILLI'.
'and' is the link.
Can you help me to learn more?
(Other definitions for chilli that I've seen before include "Hot capsicum pod" , "Small hot pod" , "Pungent pod" , "Hot-tasting dried pod used as relish or seasoning" , "Lie idly (around)" .)