M / mussĭtātor
noun

mussĭtātor

gen. mussĭtātōris · gender masculine · decl. 3rd
a silent person, a mutterer
a silent person, a mutterer, Vulg. Isa. 29, 24; cf. mussitator, ὀπογογγυστής, Vet. Gloss.—
A grumbler
A grumbler: mussitatores discent legem, Vulg. Isa. 29, 24.