Lessen from good score you, say, took in (9)
I believe the answer is:
extenuate
'lessen' is the definition.
(thesaurus)
'from good score you say took in' is the wordplay.
'from' becomes 'ex' ('from' in Latin).
'good score' becomes 'ten' (I can't explain this - if you can you should believe this answer much more).
'you say' becomes 'u' ('you' as it sounds).
'took in' becomes 'ate' (take in can mean to eat).
'ex'+'ten'+'u'+'ate'='EXTENUATE'
Can you help me to learn more?
(Other definitions for extenuate that I've seen before include "Lessen the seriousness of (an offence) with a mitigating factor" , "Mitigate" .)