"Yes; know each other through and through," assented Porfiry Petrovitch, and he screwed up his eyes, looking earnestly at Raskolnikov.
Sonia hurriedly assented.
"Yes," she assented in a faint voice.
"Yes, yes, that’s it," Lebeziatnikov assented gleefully, "that must be it, for he asked me, as soon as Sofya Semyonovna came into our room, whether you were here, whether I had seen you among Katerina Ivanovna’s guests.
There are no more uses of "assent" in the book.
Show samples from other sources
She takes my silence as assent.
Sabaa Tahir -- An Ember in the Ashes
Their murmurs of assent and disapproval gave her a sense of order and rightness.