Silent or untalkative: "Usually they were mumchance villains, but the excitement about the discovery made them chatter" (T. H. White).
[From Early Modern English mumchaunce as in to play mumchaunce, to stay silent, from mumchaunce, a kind of dice game played in silence, from Middle Low German mummenschanze (Middle Low German mummen, a dice game played in silence during Carnival, ultimately from Middle French mommon, from mommer, to play dice in a mask during Carnival, from Old French momer, to masquerade, mum; see mum2 + Middle Low German schanze, throw of dice, from Middle French chance, from Old French, throw of dice, chance; see chance) and its cognate forms Middle Dutch mommecanse and early Modern German Momschanz.]
silent; struck dumb
[C16 (masquerade, dumb show): from Middle Low German mummenschanze masked serenade; from mummen (see mummer) + schanze chance]
mumchance- To be mumchance is to be dumbstruck and silent.
See also related terms for silent.