Cynical
Etymology
From Greek "kynikos" (dog-like), from "kyon" (dog) — the nickname for the Cynic philosophers like Diogenes, mocked for living rough and shameless as dogs. Their principled contempt for convention eroded, over centuries, into today’s sense of a sneering distrust of everyone’s motives.
adjective · /SIN-ih-kul/
Assuming that people are driven by self-interest and that stated ideals are cover for it.
What it names
Reach for it to name a reflexive distrust of motives — the posture that treats every kind act as a hidden angle.
Example
He gave a cynical shrug: "They only recycle because it polishes the brand."
Related idea
Compare skeptical: a skeptic doubts a specific claim pending evidence and updates; a cynic holds a settled low view of human motives that no evidence dislodges. One is a method, the other a mood.
See also