Perhaps geeky stores beginning to restrict part of service (7)
I believe the answer is:
introit
'perhaps geeky stores beginning to restrict part of service' is the definition.
I can't tell whether this definition defines the answer.
'geeky stores beginning to restrict part of service' is the wordplay.
'geeky' becomes 'init' (I am not sure about this - if you are sure you should believe this answer much more).
'stores' means one lot of letters goes inside another.
'beginning' is a charade indicator (letters next to each other).
'part of' suggests taking the first letters (I've seen 'part' mean this).
'service' is an anagram indicator (I've seen 'serviced' mean this (to service can mean to repair)).
The first letter of 'restrict' is 'r'.
'to' put after 'r' is 'rto'.
'rto' is an anagram of 'tro'.
'init' going around 'tro' is 'INTROIT'.
Can you help me to learn more?
(Other definitions for introit that I've seen before include "Opening hymn" , "Short prayer" , "Antiphon" , "Something musical" , "Choral piece" .)