A note in an Analog science fiction magazine from the 1960’s referred to the word “mumpsimus” as a word that doesn’t mean what people are likely to think. And what a delightful word it is:
mumpsimus
noun ( pl. -muses)
A traditional custom or notion adhered to although shown to be unreasonable; a person who obstinately adheres to such a custom or notion.
ORIGIN mid 16th cent.: erroneously for Latin sumpsimus in quod in ore sumpsimus “which we have taken into the mouth” (Eucharist), in a story of an illiterate priest who, when corrected, replied “I will not change my old mumpsimus for your new sumpsimus.”
I look forward to the day when some future dictionary adds: “Synonyms: Religion, faith, Keynesian Economics.”