动摇 (dòng yáo) is a verb meaning 'to shake' or 'to undermine' in a literal sense, but more commonly used figuratively to mean 'to waver'—especially in one's beliefs, confidence, determination, or loyalty. The first character 动 (dòng) means 'to move' or 'to act', and the second 摇 (yáo) means 'to shake' or 'to sway'. Together, they vividly evoke the image of something firm losing its stability—like a tree shaken by strong wind—and thus convey a loss of inner certainty or resolve.

This word is often used in formal or serious contexts: political speeches, psychological discussions, moral debates, or personal reflections. It typically takes a noun or clause as its object (e.g., 信心、立场、决心), and is rarely used in casual daily talk. While it can describe physical shaking in rare technical or literary usage, its overwhelming modern use is abstract and psychological—referring to mental or emotional instability under pressure or doubt.