Dead language (5)
I believe the answer is:
latin
'dead language' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for latin that I've seen before include "Shakespeare's was small, according to Jonson" , "Parent language of French,Romanian" , "Language of Cicero" , "and 15 Down: Student area of Paris" , "Romantic language" .)