Convulsive describes movements or actions that are sudden, violent, and jerky, like the body is being shaken by forces it can't control. When something is convulsive, it happens in sharp, uncontrolled bursts.

The word most often describes physical reactions. Someone might experience convulsive sobs when they're crying so hard their whole body shakes. A convulsive cough racks your chest with powerful, sudden spasms. Medical conditions like seizures can cause convulsive movements where muscles contract and relax rapidly without the person being able to stop them.

The word can also describe non-physical things that feel equally sudden and overwhelming. A country might go through convulsive political changes when everything transforms dramatically in a short time. You might have a convulsive reaction to shocking news: your whole world seems to shake.

The related noun is convulsion, which describes one of these violent, shaking episodes. Notice how the word suggests something beyond ordinary control: when something is convulsive, it's both forceful and involuntary, like your body or a situation is being gripped and shaken by powerful forces.