mutterer

From mutter + -er.

mutterer (plural mutterers)

1. One who mutters.
   • 1926, Rafael Sabatini, chapter 3, in Bellarion the Fortunate‎^[1]:

     "To accuse a priest!" said someone in a tone of indignation, and a murmur arose at once in sympathy. ¶ It moved the young officer to mirth. He half-swung on his heel so as to confront those mutterers.

   • c. 1954, Jack Kerouac, Untitled poem, in Book of Sketches, 1952-57, Penguin, 2006, p. 239,

     I, mutterer to / myself in childhood French […]