1. The "vibe" or energy or affect/mood of a person or alter.
2. The visual phenomena of a migraine headache, especially scintillating scotoma.
3. The visual perception of light radiating from another person. See our thread Can you see a person's aura?
4. The many phenomena that may occur shortly before an epileptic seizure. Re this meaning of the word aura, here is a list of aura symptoms:
The Montreal Neurologic Institute classification of epileptic auras: Psychic auras were defined as cognitive (dreamy states=mixed dream and present reality; forced thinking=recurrent and stereotyped intrusive thoughts; depersonalization=sense of unreality about the self; derealization=sense of unreality about the external world; altered time sense=distorted perception of time) and noncognitive (affective=fear, anxiety and so on; illusion=modification in perception of objects, e.g., macropsia or metamorphopsia; dysmnesic=déjà vu, jamais vu; dysphasic=speech arrest or impaired comprehension; hallucinations=visual experiences). In addition to psychic auras, the other aura categories were classified according to a modified version of previously adopted classifications (visceral=epigastric rising sensation; cephalic=head pressure; somatosensory=tingling sensations, numbness and other sensations; taste/smell=smells and tastes; elementary visual=bright lights, visual blurring; warm=warmth over the trunk; elementary auditory=tinnitus; confusion=mixed-up thoughts).
What fascinates me is how many of these "epileptic aura" symptoms are common also in DID, just prior switching or when switching is being blocked.
Wikpedia: Aura (disambiguation page)
Wikpedia: Abdominal aura