punyoudaoicibaDictYouDict[pun 词源字典]
pun: [17] Snappy monosyllables produced by breaking off a piece of a longer word were all the rage in late 17th- and early 18th-century England (mob is a well-known example), and it is thought that pun may be one of them. It seems to be short for pundigrion, a short-lived fanciful 17th- and 18th-century term for a ‘pun’ or ‘quibble’ which may have been adapted from Italian puntiglio ‘nice point, quibble’ (source of English punctilious).
[pun etymology, pun origin, 英语词源]
pun (n.)youdaoicibaDictYouDict
1660s (first attested in Dryden), of uncertain origin, perhaps from pundigron, which is perhaps a humorous alteration of Italian puntiglio "equivocation, trivial objection," diminutive of Latin punctum "point." This is pure speculation. The verb also is attested from 1660s. Related: Punned; punning.
Pun was prob. one of the clipped words, such as cit, mob, nob, snob, which came into fashionable slang at or after the Restoration. [OED]