You searched for: “caput mortuum
Caput mortuum.
Dead head; death's head or a skull.
Human skull.

This was a term, or name, alchemists gave to worthless material that remained after their experiments; such as, residuum left after chemical analysis; worthless residue in a flask after the distillation was complete; by extension, "a worthless or useless person".

Word Entries at Get Words: “caput mortuum
Caput mortuum.
Death head. Residue.
This entry is located in the following unit: Graveyard words for a greater understanding of epitaphs (page 1)