It could presumably be shockingly straight (6,7)
I believe the answer is:
direct current
'it could presumably be shockingly' is the definition.
The definition suggests a singular noun which matches the answer.
'straight' is the wordplay.
I cannot quite understand how this works, but
'straight' could be 'direct' (synonyms) and 'direct' is located in the answer.
The remaining letters 'current' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for direct current that I've seen before include "Electricity flow from, eg, battery" , "Electricity flowing in one direction only" , "potentially shocking!" , "Electrically, DC" , "Electrical flow in one direction only" .)