quälen

The German word "quälen" is a verb that means "to torment" or "to torture." It conveys causing pain or distress, either physically or emotionally, to someone or something. This word can also be applicable in a figurative sense, like torturing oneself with guilt or worry.

Similar German words include "foltern" (to torture), "plagen" (to plague or afflict), and "peinigen" (to agony or to torture deeply).

The differences among these lie in their intensity and context. "Foltern" is a harsher, often physically violent verb, typically referring to severe physical torment. "Plagen" is usually less intense and can refer to ongoing nuisances or problems that cause suffering but are not as acute or drastic as torture. "Peinigen" shares a similar intensity to "quälen" and often implies a profound, continued suffering.