/sump"seuh meuhs/ , n. , pl. sumpsimuses for 2.
1. adherence to or persistence in using a strictly correct term, holding to a precise practice, etc., as a rejection of an erroneous but more common form (opposed to mumpsimus ).
2. a person who is obstinate or zealous about such strict correctness (opposed to mumpsimus ).
[ 1540-50; see MUMPSIMUS ]