Wicked graduate emptied safe (4)
I believe the answer is:
base
'wicked' is the definition.
(similar in meaning)
'graduate emptied safe' is the wordplay.
'graduate' becomes 'ba' (someone with a Bachelor of Arts degree).
'emptied' means to remove the middle letters.
'safe' with its centre removed is 'se'.
'ba'+'se'='BASE'
(Other definitions for base that I've seen before include "Ignoble - foundation" , "Shameful - headquarters" , "Low and contemptible" , "Foot; ignoble" , "Vile; basis" .)