aura

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. An invisible breath, emanation, or radiation.
2. n. A distinctive but intangible quality that seems to surround a person or thing; atmosphere: An aura of defeat pervaded the candidate's headquarters.
3. n. Pathology A sensation, as of a cold breeze or a bright light, that precedes the onset of certain disorders, such as an epileptic seizure or an attack of migraine.

Century Dictionary and Cyclopedia

1. n. A supposed influence, force, or imponderable matter proceeding from a body and surrounding it as an atmosphere; specifically, an imponderable substance supposed to emanate from all living things, to consist of the subtle essence of the individual, and to be a means of manifesting what is called animal magnetism, and also a medium for the operation of alleged mesmeric, clairvoyant, and somnambulic powers. Also called nerve-aura, or nervaura.
2. n. Figuratively, atmosphere; air; character, etc.
3. n. A peculiar sensation resembling that produced by a current of air. See epileptic aura, below.
4. n. An old native name of any South American vulture excepting the condor; an urubu, tzopilotl, gallinazo, turkey-buzzard, or carrion-crow. It was early Latinized in the form regina aurarum, was adopted by Linnæus as the specific name of his Vultur aura, and is now used as the specific name of the turkey-buzzard, Cathartes aura. See cut under Cathartes.
5. n. [capitalized] In Greek myth, a personification of the lighter winds or breezes, the divinities of the air. It was a subject frequently employed in Greek art. Pliny describes two marble statues of Auræ sailing by aid of their garments. The so-called Nereids of the famous Xanthian sepulchral monument in the British Museum are probably Auræ.

Wiktionary

1. n. Distinctive atmosphere or quality associated with something.
2. n. An invisible force surrounding a living creature.
3. n. medicine Perceptual disturbance experienced by some migraine sufferers before a migraine headache.
4. n. medicine Telltale sensation experienced by some people with epilepsy before a seizure.

GNU Webster's 1913

1. n. Any subtile, invisible emanation, effluvium, or exhalation from a substance, as the aroma of flowers, the odor of the blood, a supposed fertilizing emanation from the pollen of flowers, etc.
2. n. (Med.) The peculiar sensation, as of a light vapor, or cold air, rising from the trunk or limbs towards the head, a premonitory symptom of epilepsy or hysterics.

WordNet 3.0

1. n. a sensation (as of a cold breeze or bright light) that precedes the onset of certain disorders such as a migraine attack or epileptic seizure
2. n. a distinctive but intangible quality surrounding a person or thing
3. n. an indication of radiant light drawn around the head of a saint