What is agitated delirium?

Restless & upset. Delirium is a disturbance of consciousness or reduced clarity of awareness of the environment. Individuals with this reduced ability to pay attention and focus may also experience memory problems, disorientation, or hallucinations. Sometimes people with delirium become particularly upset or restless. This is sometimes described as "agitated delirium.".
Confusional state. Delirium is an acute state of confusion. It can be triggered by any medical illness, medication or intoxication of culprit substances. Susceptible people tend to be older, frailer, with pre-existing health conditions (e.g. Dementia). There are 2 main types of delirium: the agitated form that makes people combative and aggressive; or the hypoactive form (more common) that causes lethargy.
Hyperactive delirium. Neurology used to separate out delirium based on hyper or hypo-active motor states, but this is under scrutiny. We do not have clear evidence yet that a hypoactive delirium is biologically different from a hyperactive delirium except in regards to the very different and more straight-forward case of drug / alcohol withdrawal "delirium" which are often but not always hyperactive.
Increased activity. Likely you are referring to psychomotorically active delirium when there is increased motor activity, hallucinations and acting out. This is often classified differently from an inactive or inattentive delirium where a person cannot focus. Some police organizations have started to use this phrase without a medical rationale.
Violence 2' to fever. Delirium is what we'll referto as "waxing and waning mental status." someone will act normally or more like themselves one minute and 30 minutes later be disoriented, combative, or just act "funny." it's usually caused by illness, medication, drugs or some chemical balance such as low blood sugar or low oxygen levels. Agitated delirium is when the person is fighting verbally or physically.