Circuit used in electrical appliances (3)
I believe the answer is:
lap
'circuit' is the definition.
('lap' can be a synonym of 'circuit')
'in electrical appliances' is the wordplay.
'in' indicates a hidden word.
'LAP' is hidden within 'electrical appliances'.
'used' acts as a link.
(Other definitions for lap that I've seen before include "One complete circuit" , "Sports circuit" , "Thighs, when seated" , "Knees" , "Drink (like dog), circuit" .)