Denied safety device is in shade (7)
I believe the answer is:
refused
'denied' is the definition.
('refuse' can be a synonym of 'deny')
'safety device is in shade' is the wordplay.
'safety device' becomes 'fuse' (electronic safety device).
'is in' is an insertion indicator.
'shade' becomes 'red' (red is a colour or shade).
'fuse' inserted inside 'red' is 'REFUSED'.
(Other definitions for refused that I've seen before include "Was unwilling to accept" , "Declined, rejected" , "turned down appeal" , "Not accepted" , "Said no (7)" .)