cynical

Believing that people are motivated purely by self-interest; distrustful of human goodness or sincerity.

• cynicism/ˈsɪnɪsɪzəm/(n)愤世嫉俗
• cynic/ˈsɪnɪk/(n)愤世嫉俗者
• cynically/ˈsɪnɪkli/(adv)

• cynical about
• cynical view
• growing cynical
• cynical remark
• deeply cynical

1. 1.Years of broken political promises had made the voters deeply cynical about reform. (distrustful)
2. 2.It was a cynical marketing ploy — the company donated a penny per purchase while charging ten dollars more. (exploitative)

• skeptical/ˈskɛptɪkl/— doubting — less negative
• pessimistic/ˌpɛsɪˈmɪstɪk/— expecting the worst
• jaded/ˈdʒeɪdɪd/— tired and lacking enthusiasm after too much experience

from Greek "kynikos" (dog-like) — the Cynic philosophers (like Diogenes) rejected social conventions, living like dogs — the word shifted from philosophical asceticism to general distrust