Entirely lacking in depth, video nasty (6)
I believe the answer is:
devoid
'entirely lacking' is the definition.
(I've seen this before)
'depth video nasty' is the wordplay.
'depth' becomes 'd' (abbreviation in geometry).
'nasty' indicates anagramming the letters (a nasty or wrong spelling).
'video' is an anagram of 'evoid'.
'd'+'evoid'='DEVOID'
'in' acts as a link.
(Other definitions for devoid that I've seen before include "Empty - do dive (anag)" , "Empty or free from" , "Bereft" , "Completely lacking" , "Entirely free (of)" .)