shibboleth

Definitions

A custom, principle, or belief distinguishing a particular class or group of people, especially a long-standing one regarded as outmoded or no longer important.

A word or pronunciation that distinguishes people of one group or class from those of another.

Examples

The secret password served as a shibboleth to distinguish the members of the inner circle from the outsiders.

For many in the industry, the belief that bigger is always better has become an outdated shibboleth.

Synonyms

catchphrase slogan watchword password platitude byword motto

Antonyms

original thought novel idea unique expression unconventional concept