He says whose turn is next (7)
I believe the answer is:
compere
'he says whose turn is next' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
This is all the clue.
Can you help me to learn more?
(Other definitions for compere that I've seen before include "host show" , "Master of ceremonies" , "(Male) show introducer" , "TV presenter?" , "M.C." .)