Old soldier’s language in court! (7)
I believe the answer is:
chindit
'old soldier's' is the definition.
Both the definition and answer are singular nouns.
Perhaps there's a link between them I don't understand?
'language in court' is the wordplay.
'language' becomes 'hindi' (Hindi is an example).
'in' is an insertion indicator.
'court' becomes 'ct' (abbreviation used in road names).
'hindi' put within 'ct' is 'CHINDIT'.
Can you help me to learn more?
(Other definitions for chindit that I've seen before include "WW2 allied commando in Burma" , "Burmese fighter" , "Old fighter in Burma" , "WW2 soldier" .)