(sin′ik) noun
A sneering, captious person; a misanthrope; pessimist.
—adjective
1. Pertaining to Sirius, the Dog Star.
2. Rare Of or like a dog.
3. Cynical. [<Gk. kynikos doglike]

(sin′ik) noun
One of a sect of Greek philosophers of the fifth and fourth centuries B.C., who held that virtue, rather than intellectual or sensual pleasure, was the ultimate goal of life: their doctrine gradually came to symbolize insolent self-righteousness.
—adjective Belonging to or like the Cynics: also Cyn′i·cal.