One of the great forenames (5)
I believe the answer is:
peter
'one of the great forenames' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'one of the' is the wordplay.
I cannot quite understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
The remaining letters 'peer' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for peter that I've seen before include "foundation for church" , "prison cell" , "-- Sellers, comic actor" , "Safe; saint" , "Cephas" .)