mumpsimus

[muhmp-suh-muh s]

noun, plural mump·si·mus·es for 2.

adherence to or persistence in an erroneous use of language, memorization, practice, belief, etc., out of habit or obstinacy (opposed to sumpsimus).
a person who persists in a mistaken expression or practice (opposed to sumpsimus).

Origin of mumpsimus

1520–30; from a story, which perhaps originated with Erasmus, of an illiterate priest who said mumpsimus rather than sūmpsimus (1st plural perfect indicative of Latin sūmere to pick up; see consume) while reciting the liturgy, and refused to change the word when corrected

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for mumpsimus

Historical Examples of mumpsimus

We are not going to change our old 'mumpsimus' for anybody's new 'sumpsimus.'
Res Judicat
Augustine Birrell
Mr. Beckford called the beast, or reptile, a mumpsimus (sic).
Recollections of the late William Beckford
Henry Venn Lansdown
Mumpsimus, mump′si-mus, n. an error to which one clings after it has been thoroughly exposed.
Chambers's Twentieth Century Dictionary (part 2 of 4: E-M)
Various