coffinyoudaoicibaDictYouDict[coffin 词源字典]
coffin: [14] Greek kóphinus meant ‘basket’. It passed via Latin cophinus into Old French, where it split into two words. Cofin came to mean ‘box, chest’ as well as ‘basket’, and it was with these senses that it was borrowed into English. The specific application to boxes for burial is not recorded before the early 16th century. The other Old French descendant of Latin cophinus was coffre, which gave English coffer [13].
=> coffer[coffin etymology, coffin origin, 英语词源]
coffin (n.)youdaoicibaDictYouDict
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," which is 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.