Let in or on (8)
I believe the answer is:
admitted
'let in' is the definition.
(I've seen this in another clue)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for admitted that I've seen before include "being given access" , "Owned up or let in" , "Allowed in or accepted as true" , "Conceded; let in" , "Confessed; let in" .)