puddingyoudaoicibaDictYouDict[pudding 词源字典]
pudding: [13] The original puddings were sausages – whose present-day survivor is the black pudding. They were encased in the intestines or stomachs of animals, and it was this casing that provided the spring-board for the word’s subsequent development in meaning. It came to be applied to any food cooked in a bag (hence the cannon-ball shape of the traditional Christmas pudding).

Such dishes could be savoury (like today’s steak-and-kidney pudding) or sweet, but it was not until the 20th century that pudding came to be used specifically for the ‘sweet course of a meal’. The word comes via Old French boudin from Vulgar Latin *botellīnus, a diminutive form of Latin botellus ‘sausage’ (source of English botulism).
=> botulism[pudding etymology, pudding origin, 英语词源]
pudding (n.)youdaoicibaDictYouDict
c. 1300, "a kind of sausage: the stomach or one of the entrails of a pig, sheep, etc., stuffed with minced meat, suet, seasoning, boiled and kept till needed," perhaps from a West Germanic stem *pud- "to swell" (cognates: Old English puduc "a wen," Westphalian dialect puddek "lump, pudding," Low German pudde-wurst "black pudding," English dialectal pod "belly;" also see pudgy).

Other possibility is the traditional one that it is from Old French boudin "sausage," from Vulgar Latin *botellinus, from Latin botellus "sausage" (change of French b- to English p- presents difficulties, but compare purse (n.)). The modern sense had emerged by 1670, from extension to other foods boiled or steamed in a bag or sack (16c.). German pudding, French pouding, Swedish pudding, Irish putog are from English. Pudding-pie attested from 1590s.