A little current rattles me, given a shock (9)
I believe the answer is:
streamlet
'a little current' is the definition.
'rattles me given a shock' is the wordplay.
'given a shock' is an anagram indicator.
'rattles'+'me'='rattlesme'
'rattlesme' with letters rearranged gives 'STREAMLET'.
(Other definitions for streamlet that I've seen before include "small brook" , "hardly a river" , "running water" , "Burn" .)