Brief electricity failure (5)
I believe the answer is:
short
This clue might be a double definition.
'brief' is the first definition.
(synonyms)
'electricity failure' is the second definition.
'short' can be an answer for 'failure' (short is a kind of failure). I am not sure about the 'electricity' bit.
Can you help me to learn more?
(Other definitions for short that I've seen before include "Terse; in insufficient supply" , "Neat" , "Wanting" , "Not long enough" , "Uncivil, brief film" .)