Some current map adjusted before (6)
I believe the answer is:
ampere
'some current' is the definition.
(amperes measure electrical current)
'map adjusted before' is the wordplay.
'adjusted' indicates an anagram.
'before' becomes 'ere' (poetic term for 'before').
'map' with letters rearranged gives 'amp'.
'amp'+'ere'='AMPERE'
(Other definitions for ampere that I've seen before include "Solenoid inventor" , "Current measure" , "scientist" , "Unit measured by 17 across" , "Unit of currency" .)