In contemporary usage the word has acquired an extended meaning which is often cited first (and sometimes even exclusively) in shorter dictionaries, namely, an old belief or saying which is cited repetitively or unreflectively but which is, or may be, fallacious or untrue.

The term originates from the Hebrew word shibbólet (שִׁבֹּלֶת), which literally means the part of a plant containing grains, such as an ear of corn or a stalk of grain or, in different contexts, "stream, torrent". The modern use derives from an account in the Hebrew Bible, in which pronunciation of this word was used to distinguish Ephraimites, whose dialect lacked a /ʃ/ phoneme (as in shoe), from Gileadites, whose dialect did include such a phoneme.