Synthetic tongue person ate anyhow (9)
I believe the answer is:
esperanto
'synthetic tongue' is the definition.
'esperanto' can be an answer for 'tongue' (I've seen this before). I'm not sure about the 'synthetic' bit.
'person ate anyhow' is the wordplay.
'anyhow' indicates an anagram.
'person'+'ate'='personate'
'personate' is an anagram of 'ESPERANTO'.
Can you help me to learn more?
(Other definitions for esperanto that I've seen before include "Language invented by Dr Zamenhof" , "Artificial speech-form" , "No repeats of this artificial language, strangely" , "Artificial language invented for international use" , "artificial tongue" .)