Function:
* Funereal: Emphasizing its association with death and burial.
* Mortuary: Related to the dead or burial.
* Sepulchral: Suggesting a tomb or burial place.
* Tomb-like: Describing its resemblance to a tomb.
Appearance:
* Stone: If it's made of stone.
* Ornate: If it's elaborately decorated.
* Ancient: If it's old.
* Grand: If it's impressive in size or design.
You can also use metaphorical adjectives depending on the context:
* Silent: To emphasize its stillness and the absence of life.
* Eternal: To suggest its enduring nature.
Ultimately, the best adjective depends on the specific context and what you want to emphasize about the sarcophagus.