Pallet on the right shows damage (6)
I believe the answer is:
crater
'damage' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'pallet on the right' is the wordplay.
I cannot quite understand how this works, but
'on' could be 'at' (I've seen this in other clues) and 'at' is found within the answer.
'right' could be 'r' (common abbreviation) and 'r' is found in the answer.
This explanation may well be incorrect...
'shows' acts as a link.
Can you help me to learn more?
(Other definitions for crater that I've seen before include "Volcano's mouth" , "Bowl-shaped cavity as on volcano peak" , "Hole left by bomb" , "Capital of Virginia" , "Hole (on the moon?)" .)