mumpsimus noun. ['mʌmpsɪmǝs] Now literary. M16.
[Erron. for Latin sumpsimus in quod in ore sumpsimus 'which we have taken into the mouth' (in the Eucharist), in a story of an illiterate priest who, when corrected, replied 'I will not change my old mumpsimus for your new sumpsimus'.]
1. An obstinate adherent of old ways, in spite of clear evidence of their error; an ignorant and bigoted opponent of reform. Formerly also loosely, an old fogey. M16.

2. A traditional custom or notion obstinately adhered to although shown to be unreasonable. M16.

[TahlilGaran] English Dictionary ▲