Old court letter exposed Group of Eight (7)
I believe the answer is:
octette
'group of eight' is the definition.
(I've seen this before)
'old court letter exposed' is the wordplay.
'old' becomes 'o' (abbreviation).
'court' becomes 'ct' (abbreviation used in road names).
'exposed' says to take the centre (outside letters removed).
The central letters of 'letter' are 'ette'.
'o'+'ct'+'ette'='OCTETTE'
(Other definitions for octette that I've seen before include "Eight musicians" , "Noted work" , "Group of eight" .)