Possibly start with Latin, changing it back to English? (9)
I believe the answer is:
translate
'english?' is the definition.
(thesaurus)
'possibly start with latin changing it back' is the wordplay.
I cannot really see how this works, but
'latin' could be 'late' (Late Latin is an example) and 'late' is found within the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is located in the answer.
This may be the basis of clue (or it may be nonsense).
'to' acts as a link.
(Other definitions for translate that I've seen before include "Switch language" , "make comprehensible" , "Put in other words" , "Express (words) in another language" , "Put into another language" .)