Superficial variety in ooze (4-4)
I believe the answer is:
skin-deep
'superficial' is the definition.
(I've seen this before)
'variety in ooze' is the wordplay.
'variety' becomes 'kind' (synonyms).
'in' is an insertion indicator.
'ooze' becomes 'seep' (synonyms).
'kind' placed within 'seep' is 'SKIN-DEEP'.
(Other definitions for skin-deep that I've seen before include "Superficial (like beauty?)" , "Superficial, beauty perhaps" , "Superficial like body graze" , "The depth of beauty" , "Stringed instrument" .)