A poem that could shock? (5)
I believe the answer is:
anode
'a poem that could shock?' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'a poem' is the wordplay.
'a' becomes 'an'.
'poem' becomes 'ode' (ode is a type of poem).
'an'+'ode'='ANODE'
Can you help me to learn more?
(Other definitions for anode that I've seen before include "Opposite to cathode" , "A cell terminal" , "Electrical terminal" , "Positive terminal" , "Electrical pole" .)