Language one's pater translated (9)
I believe the answer is:
esperanto
'language' is the definition.
(Esperanto is an example)
'one's pater translated' is the wordplay.
'translated' indicates anagramming the letters.
'ones'+'pater'='onespater'
'onespater' anagrammed gives 'ESPERANTO'.
(Other definitions for esperanto that I've seen before include "Dr Zamenhof's language" , "composite language" , "Language invented by Dr Zamenhof" , "No repeats of this artificial language, strangely" , "Personate in artificial language" .)