Observer with the right to check? (4)
I believe the answer is:
seer
'observer' is the definition.
(one who observes or sees)
'right to check?' is the wordplay.
'right' becomes 'r' (common abbreviation).
'to' is a charade indicator (letters next to each other) (I've seen this in other clues).
'check?' becomes 'see' ('see' can be a synonym of 'check').
'r' put after 'see' is 'SEER'.
'with the' is the link.
(Other definitions for seer that I've seen before include "Clairvoyant, visionary" , "Person who can read the future" , "Prophet or clairvoyant" , "Soothsayer" , "He forecasts" .)