Dead? Case of not being buried (6)
I believe the answer is:
latent
'being buried' is the definition.
(thesaurus)
'dead? case of not' is the wordplay.
'dead?' becomes 'late' ('late' can be similar in meaning to 'dead').
'case of' means to remove the middle letters (like emptying a case).
'not' with its centre removed is 'nt'.
'late'+'nt'='LATENT'
(Other definitions for latent that I've seen before include "There but not yet effective" , "Hidden (potential)" , "Not (yet) apparent" , "Potential not realised" , "'Hidden, undeveloped (6)'" .)