Author's latest books inspired by this, but in Latin accent (6)
I believe the answer is:
rhotic
'accent' is the definition.
(rhotic accent is a type of accent)
'author's latest books inspired by this but in latin' is the wordplay.
'latest' says to take the final letters.
'books' becomes 'OT' (abbreviation for Old Testament).
'inspired by' is an insertion indicator (some letters breathed in or 'inspired' by others).
'this but in latin' becomes 'hic' ('hic' is 'this' in Latin).
The final letter of 'author' is 'r'.
'ot' going inside 'hic' is 'hotic'.
'r'+'hotic'='RHOTIC'
(Another definition for rhotic that I've seen is " pronouncing a particular letter".)