Constant checking by particular type of examiner (8)
I believe the answer is:
external
'particular type of examiner' is the definition.
I can't judge whether this definition defines the answer.
'constant checking by' is the wordplay.
'constant' becomes 'eternal' (I've seen this before).
'checking' indicates putting letters inside (check can mean to control or arrest).
'by' becomes 'x' (t by r is t x r).
'eternal' going around 'x' is 'EXTERNAL'.
Can you help me to learn more?
(Other definitions for external that I've seen before include "involving foreign nations" , "Relating to the outside" , "Lying outside" , "Belonging to the outside" , "Superficial" .)