Examination of a Buddhist at regular intervals (5)
I believe the answer is:
audit
'examination' is the definition.
(I've seen this before)
'a buddhist at regular intervals' is the wordplay.
'at regular intervals' indicates alternate letters.
The alternate letters of 'buddhist' are 'udit'.
'a'+'udit'='AUDIT'
'of' acts as a link.
(Other definitions for audit that I've seen before include "Verify accounts" , "Examine accounts" , "Inspection of records" , "Conduct annual check of firm's accounts" , "Examination of accounts" .)