Where an admission is made (5)
I believe the answer is:
inlet
'where an admission is made' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
This is the entire clue.
Can you help me to learn more?
(Other definitions for inlet that I've seen before include "Small opening of coastline" , "Gulf" , "Small arm of the sea" , "Entry port" , "Opening through which fluid can pass" .)