Lacking in power, as to act effectively; helpless: “Technology without morality is barbarous; morality without technology is impotent” (Freeman J. Dyson)
If someone feels impotent, they feel that they have no power to influence people or events. The aggression of a bully leaves people feeling hurt, angry and impotent = powerless
Lacking in power, as to act effectively; helpless: "Technology without morality is barbarous; morality without technology is impotent" (Freeman J. Dyson)