shibbolethyoudaoicibaDictYouDict[shibboleth 词源字典]
shibboleth: [14] Hebrew shibbōleth meant ‘stream’. According to the Bible, the Gileadites used it as a password, for they knew their enemies the Ephraimites could not pronounce the sh properly (‘And it was so, that when those Ephraimites which were escaped said, Let me go over; that the men of Gilead said unto him, Art thou an Ephraimite? If he said, Nay, then they said unto him, Say now Shibboleth: and he said Sibboleth: for he could not frame to pronounce it right’, Judges 12:5–6).

In 17th-century English it came to be applied generically to any word used as a test of pronunciation, particularly as a sign of belonging to a group, and hence by extension to any catchword or slogan adopted by a group, and this eventually evolved into the modern sense ‘outmoded slogan, practice, etc still adhered to’.
[shibboleth etymology, shibboleth origin, 英语词源]
shibboleth (n.)youdaoicibaDictYouDict
late 14c., the Hebrew word shibboleth, meaning "flood, stream," also "ear of corn;" in Judges xii:4-6. It was the password used by the Gileadites to distinguish their own men from fleeing Ephraimites, because Ephraimites could not pronounce the -sh- sound. Hence the figurative sense of "watchword" (first recorded 1630s), which evolved by 1862 to "outmoded slogan still adhered to." A similar test-word was cicera "chick pease," used by the Italians to identify the French (who could not pronounce it correctly) during the massacre called the Sicilian Vespers (1282).