Слово "flatness". Англо-русский словарь Мюллера

His glance was keen but showed cunning rather than intelligence; his lips were straight, and so thin that, as they closed, they were drawn in over the teeth; his cheek-bones were broad and projecting, a never-failing proof of audacity and craftiness; while the flatness of his forehead, and the enlargement of the back of his skull, which rose much higher than his large and coarsely shaped ears, combined to form a physiognomy anything but prepossessing, save in the eyes of such as considered that the owner of so splendid an equipage must needs be all that was admirable and enviable, more especially when they gazed on the enormous diamond that glittered in his shirt, and the red ribbon that depended from his button-hole.

“To women who please me only by their faces, I am the very devil when I find out they have neither souls nor hearts—when they open to me a perspective of flatness, triviality, and perhaps imbecility, coarseness, and ill-temper: but to the clear eye and eloquent tongue, to the soul made of fire, and the character that bends but does not break—at once supple and stable, tractable and consistent—I am ever tender and true.”

His quaint blending of Essex flatness with saintly simplicity continuously amused the Frenchman till the priest arrived (somehow) at Tottenham with all his parcels, and came back for his umbrella. When he did the last, Valentin even had the good nature to warn him not to take care of the silver by telling everybody about it.

“To women who please me only by their faces, I am the very devil when I find out they have neither souls nor hearts—when they open to me a perspective of flatness, triviality, and perhaps imbecility, coarseness, and ill-temper: but to the clear eye and eloquent tongue, to the soul made of fire, and the character that bends but does not break—at once supple and stable, tractable and consistent—I am ever tender and true.”

The flatness was all gone out of her voice. "Come over, please.