What is the X in X-mas?
early 14c., "chest or box for valuables," from Old French cofin "sarcophagus," earlier "basket, coffer" (12c., Modern French coffin), from Latin cophinus "basket, hamper" (source of Italian cafano, Spanish cuebano "basket"), from Greek kophinos "a basket," of uncertain origin.
Funeral sense in English is 1520s; before that it was the literal Latin one and had also a meaning of "pie crust" (late 14c.). Meaning "vehicle regarded as unsafe" is from 1830s. Coffin nail "cigarette" is slang from 1880; nail in (one's) coffin "thing that contributes to one's death" is from 1792.
used in Gen. 50:26 with reference to the burial of Joseph. Here, it means a mummy-chest. The same Hebrew word is rendered "chest" in 2 Kings 12:9, 10.
the receptacle in which a corpse is confined. The Greeks and Romans disposed of their dead both by burial and by cremation. Greek coffins were urn-shaped, hexagonal, or triangular, with the body arranged in a sitting posture. The material used was generally burnt clay and in some cases had obviously been molded around the body and baked. In the Christian era stone coffins came into use. Romans who were rich enough had their coffins made of a limestone brought from Assus, in Asia Minor, which was commonly believed to "eat" the body