Both Uses

self-righteous
in
And Then There Were None
(Edited)

There was no self-reproach, no uneasiness in those eyes. They were hard and self-righteous.
p. 112.1 *

self-righteous = convinced of personal moral superiority

editor's notes: This is in reference to Emily Brent who immediately fired and kicked out of her home the unmarried servant who became pregnant. "No self-reproach" means Brent did not in any way blame herself for contributing to the problems that led the girl to commit suicide.
Self-righteous smug old hypocrite.
p. 231.6

self-righteous = convinced of personal moral superiority

Definitions:

(1) (self-righteous)
believing oneself morally superior to others -- especially in an annoying manner
(2) (meaning too rare to warrant focus)