Mull over change in text that bored China (8)
I believe the answer is:
meditate
'mull over' is the definition.
(synonyms)
'change in text that bored china' is the wordplay.
I cannot quite understand how this works, but
'change' could be 'edit' (editing is a kind of changing) and 'edit' is found within the answer.
'china' could be 'mate' (china plate is Cockney rhyming slang for mate) and 'mate' is located in the leftover letters.
No letters remain.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for meditate that I've seen before include "Consider thoughtfully" , "Think contemplatively" , "Focus one's mind for a period for spirituality or relaxation" , "Think to relax one's mind" , "Reflect upon" .)