noun, plural mump·si·mus·es for 2.
Origin of mumpsimus
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
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.