Buzz existed in reception (5)
I believe the answer is:
whirr
'reception' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'buzz existed' is the wordplay.
'buzz' becomes 'whir' (I have seen 'Prolonged buzz ' mean 'whir' so perhaps 'buzz' could also mean 'whir').
'existed' becomes 'r' (I can't justify this - if you can you should give a lot more credence to this answer).
'whir'+'r'='WHIRR'
'in' is the link.
Can you help me to learn more?
(Other definitions for whirr that I've seen before include "Revolve humming" , "Sound of vibrations" , "Sound of vibration" , "Spin noisily" , "Turn" .)