All 4 Uses

sinister
in
The Souls of Black Folk
(Edited)

It would be unjust to Mr. Washington not to acknowledge that in several instances he has opposed movements in the South which were unjust to the Negro; he sent memorials to the Louisiana and Alabama constitutional conventions, he has spoken against lynching, and in other ways has openly or silently set his influence against sinister schemes and unfortunate happenings.
Chpt 3

sinister = evil, harmful, or frightening
And men ask this to-day all the more eagerly because of sinister signs in recent educational movements.
Chpt 6 *
The shadowy, formless thing—the temptation of Hate, that hovered between him and the world—grew fainter and less sinister.
Chpt 12
Tall and black, they move slowly by, and seem in the sinister light to flit before the city like dim warning ghosts.
Chpt 13

Definitions:

(1) (sinister)
evil or harmful; or making an evil or frightening impression
(2) (meaning too rare to warrant focus)
Much more rarely and only in very old usage, sinister can refer to the left side of something.