All 4 Uses of

disdain
in
Notes from the Underground

Those moans express in the first place all the aimlessness of your pain, which is so humiliating to your consciousness; the whole legal system of nature on which you spit disdainfully, of course, but from which you suffer all the same while she does not.†
Chpt 1.4 *

disdainfully = with a lack of respect; or with a sense of superiority

But I was already a tyrant at heart; I wanted to exercise unbounded sway over him; I tried to instil into him a contempt for his surroundings; I required of him a disdainful and complete break with those surroundings.†
Chpt 2.3

disdainful = full of disrespect

With despair I pictured to myself how coldly and disdainfully that "scoundrel" Zverkov would meet me; with what dull-witted, invincible contempt the blockhead Trudolyubov would look at me; with what impudent rudeness the insect Ferfitchkin would snigger at me in order to curry favour with Zverkov; how completely Simonov would take it all in, and how he would despise me for the abjectness of my vanity and lack of spirit—and, worst of all, how paltry, UNLITERARY, commonplace it would all be.†
Chpt 2.3

disdainfully = with a lack of respect; or with a sense of superiority

Definition:

to disrespect or reject as unworthy