Examination of a Buddhist at regular intervals (5)
I believe the answer is:
audit
'examination' is the definition.
(I know that audit is a type of examination)
'a buddhist at regular intervals' is the wordplay.
'at regular intervals' indicates alternate letters.
The alternating 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" .)