The writer backed inclination to suppress old stupid expression (10)
I believe the answer is:
embodiment
'expression' is the definition.
(thesaurus)
'the writer backed inclination to suppress old stupid' is the wordplay.
I cannot quite understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
'writer' could be 'me' (the person who wrote the clues) and 'me' is located in the answer.
'old' could be 'o' (common abbreviation eg in OE for Old English) and 'o' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for embodiment that I've seen is " Personification".)