In early use (Medicine): = phrenitis, n. Later also (more generally): madness, frenzy.

A disease affecting children, characterized by inflammation of the brain and membranes, and burning fever. Cf. sideration, n. 2c.

Delirium, esp. when associated with or attributed to inflammation of the brain; inflammation of the brain or of the meninges, encephalitis or…

Inflammation of the brain or meninges; encephalitis or meningitis; a disease (supposedly) characterized or accompanied by such inflammation.

B. Rush's name for: oedema of the brain, esp. as an early stage of acute hydrocephalus or an inflammatory process; (also) an instance of this.

‘Inflammation of the brain and its membranes; all inflammatory conditions of the central nervous system’ (New Sydenham Soc. Lexicon).

Inflammation of the substance of the brain.