With poles, carrying current mechanical beings (8)
I believe the answer is:
androids
'mechanical beings' is the definition.
'with poles carrying current' is the wordplay.
'with' becomes 'and'.
'poles' becomes 'rods' ('rod' can be a synonym of 'pole').
'carrying' indicates putting letters inside.
'current' becomes 'i' (symbol for electric current).
'rods' going around 'i' is 'roids'.
'and'+'roids'='ANDROIDS'
(Other definitions for androids that I've seen before include "Communication devices" , "Robots that resemble humans" , "Human-looking robots" , "Automatons that resemble humans" , "Robots in human form as in science fiction" .)