The Hebrew word Shibboleth literally means "torrent of water". In the Bible, the term was used to distinguish members of a group whose dialect lacked a "sh" sound, using an "s" in its place, from members of a group whose dialect included such a sound.
In modern parlance, the term is used for phrases that are used in a similar way--only members who belong to a certain group can use them "correctly." More loosely, "shibboleth" is also sometimes used for words or phrases that form part of the specialized jargon of a group, and reveal their users as members of a group.
- And the Gileadites seized the passages of the Jordan before the Ephraimites; and it was so, that when those Ephraimites who had escaped said, "Let me go over," that the men of Gilead said unto him, "Art thou an Ephraimite?" If he said, "Nay," then said they unto him, "Say now 'Shibboleth.'" And he said "Sibboleth," for he could not frame to pronounce it right. Then they took him and slew him at the passages of the Jordan; and there fell at that time of the Ephraimites forty and two thousand. (Judges 12:5-6, King James Version of the Bible)
- Scheveningen: Dutch people pronounce this word beginning with separate "s" [s] and "ch" [x]; a German would pronounce sch as [ʃ] = SAMPA [S]. The Dutch Resistance used this to ferret out Nazi spies during World War II.
- Ripley/ripply: If any distinction is made between the two words by a native speaker (rip-lee vs. rip-ul-ee), one will almost certainly not be made by a native speaker of Japanese. Either pronunciation would be very difficult to say properly as the English distinction between the R and L sounds is not present in Japanese.
- Leghorn: Allegedly, this word was used as a shibboleth during a war between the Chinese and Japanese, since the Japanese pronounced it as 'reghorn' (not being able to pronounce l), and the Chinese as 'legholn' (not being able to say English r). In fact, both Japanese and Chinese only have one phoneme /r/ (and no /l/ phoneme), with different allophones.
- Fish and chips: Australians and New Zealanders sometimes tease each other on its pronunciation, usually as a joke. To Australians, it sounds like Kiwis pronounce it "fush and chups"
- South Island and North Island: New Zealanders would never dream of saying they lived on one of their main islands - neither would they talk about South Island or North Island, despite what atlases usually denote. New Zealanders live in The North Island or in The South Island.
- The Spanish word perejil (parsley) was used as a shibboleth by Trujillo; see http://www.ling.upenn.edu/courses/Fall_2003/ling001/shibboleth.html