Wicked soul emptied safe (4)
I believe the answer is:
base
'wicked' is the definition.
('base' can be similar in meaning to 'wicked')
'soul emptied safe' is the wordplay.
'soul' becomes 'ba' (term for the soul in ancient Egypt).
'emptied' suggests removing the centre.
'safe' with its centre taken out is 'se'.
'ba'+'se'='BASE'
(Other definitions for base that I've seen before include "Venial; headquarters" , "Ignoble; starting point" , "Ignoble; low part" , "Bottom; vile" , "Starting point; wicked" .)