shibboleth

The Story of the Shibboleth A shibboleth is a kind of linguistic password: A way of speaking (a pronunciation, or the use of a particular expression) that identifies one as a member of an 'in' group. The purpose of a shibboleth is exclusionary as much as inclusionary: A person whose way of speaking violates a shibboleth is identified as an outsider and thereby excluded by the group. (This phenomenon is part of the "Judge a …

…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 say Nay; 6 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 Jordan: and there fell at that time of the Ephraimites forty and two thousand.