Preserve a body (6)
I believe the answer is:
embalm
'preserve a body' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for embalm that I've seen before include "Treat corpse so as to retard decay" , "Preserve body, mummify" , "Prepare for burial" , "Use chemicals to preserve a dead body from decay" , "Prepare corpse for preservation (6)" .)