Which person has come to a stop? (4)
I believe the answer is:
whoa
'stop?' is the definition.
(command to stop a horse)
'which person has come to a' is the wordplay.
I cannot really understand how this works, but
'a' is found in the answer.
'which person' could be 'who' (I've seen this in another clue) and 'who' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for whoa that I've seen before include "Hold your horses!" , "Stop, Dobbin!" , "Said to stop a horse" , "Cry for horses to stop" , "The King of rock and roll" .)