All 7 Uses

sinister
in
The Lords of Discipline
(Edited)

He gave me a look that linked us as spiritual allies, resolute desperadoes in headlong flight from the false and sinister veneer of Charleston.
Chpt 1.2 *

sinister = evil, harmful, or frightening
When I finally could look up and my eyes could focus, Pig had entered that first sinister position of karate, and Mark stood facing him, resolute and dangerous, in a boxer's stance of at least equal formidability.
Chpt 1.10
There was a runaway luxuriance to the garden's ruined profusion that made it seem sinister instead of tranquil.
Chpt 1.13
But there was another rumor that sounded far more sinister.
Chpt 2.17
Nothing has really happened that's bad or sinister.
Chpt 3.30
I was shaking again, not from revulsion at what I had done, but from something more sinister.
Chpt 4.36
As we sat there, we heard the drummers begin their cold tattoo of banishment on the parade ground, heard its sinister echo as it pulsed along the galleries of the four battalions, as it summoned the regiment for the drumming out.
Chpt 4.41

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.