Coffins made of stone or terracotta, generally ornamented with sculpture or carving and of a size large enough to contain the entire body. Antique examples were often extensively decorated with relief sculpture, which were highly influential on Renaissance artists. Many sarcophagi were also produced in the Baroque and Neoclassical eras. Pliny explains that the derivation of the word ("flesh eating" in Greek) refers specifically to coffins of limestone from the Troad (the region around Troy), which was believed to cause rapid dissolving of the body; more probably, the term refers to various religious and folkloristic ideas that resulted in calling any coffin a body eater. The word came into general use as the name for any large stone coffin in imperial Rome, and is now generally used to refer to large, ornate stone coffins from any period or place.

Source: AAT

http://vocab.getty.edu/page/aat/300005947