Noah Webster
Shibboleth
SHIB'BOLETH, noun [Heb. an ear of corn, or a stream of water.]
1. A word which was made the criterion by which to distinguish the Ephraimites not being able to pronounce the letter sh, pronounced the word sibboleth. See Judges 12:6. Hence,
2. The criterion of a party; or that which distinguishes one party from another; and usually some peculiarity in things of little importance.