Emily Dickinson Lexicon

SHIB'BO-LETH, n. [Heb. an ear of corn, or a stream of water.]

1. A word which was made the criterion by which to distinguish the Ephraimites from the Gileadites. The Ephraimites not being able to pronounce the letter ש sh, pronounced the word sibboleth. See Judges xii. Hence,
2. The criterion of a party; or that which distinguishes one party from another; and usually, some peculiarity in things of little importance. – South.