Tongue in gelatine (5)
I believe the answer is:
latin
'tongue' is the definition.
(Latin is an example)
'in gelatine' is the wordplay.
'in' indicates the answer is hidden within the clue.
'LATIN' can be found hidden inside 'gelatine'.
(Other definitions for latin that I've seen before include "The language of old Rome" , "Language of old Romans" , "A Romance language" , "Ancestor of French, Romanian" , "Hispanic, for example" .)