If a dead person is embalmed, their body is preserved using special substances. His body was embalmed. the embalmed body of Lenin. to treat a dead body with chemicals, oils etc to prevent it from decaying
To anoint all over with balm; especially, to preserve from decay by means of balm or other aromatic oils, or spices; to fill or impregnate (a dead body), with aromatics and drugs that it may resist putrefaction
[ im-'bä(l)m, New Englan ] (transitive verb.) 14th century. Middle English embaumen, from Middle French embaumer, from Old French embasmer, from en- + basme balm; more at BALM.