A language from overseas (4)
I believe the answer is:
erse
'a language' is the definition.
(historical term for Scottish Gaelic)
'from overseas' is the wordplay.
'from' indicates a hidden word.
'ERSE' is hidden in the letters of 'overseas'.
(Other definitions for erse that I've seen before include "Possibly the language" , "Old Celtic language" , "Old name for Celtic languages" , "Old language spoken by strange seer" , "Celtic tongue" .)