phenomenon

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. An occurrence, circumstance, or fact that is perceptible by the senses.
2. n. An unusual, significant, or unaccountable fact or occurrence; a marvel.
3. n. A remarkable or outstanding person; a paragon. See Synonyms at wonder.
4. n. Philosophy In the philosophy of Kant, an object as it is perceived by the senses, as opposed to a noumenon.
5. n. Physics An observable event.

Century Dictionary and Cyclopedia

1. n. An obsolete form of phenomenon.
2. n. In philosophy, an appearance or immediate object of experience, as distinguished from a thing in itself.
3. n. In science, a fact directly observed, being either
4. n. an individual circumstance or occurrence, such as the emergence of a temporary star, or more usually
5. n. a regular kind of fact observed on certain kinds of occasion, such as the electrical sparks seen in combing the hair of some persons in cold, dry weather.
6. n. Ay extraordinary occurrence or fact in nature; something strange and uncommon; a prodigy; a very remarkable personage or performer.
7. n. Any physiological or pathological change apparent to the senses.
8. n. Diminution of the Achilles tendon reflex in sciatica.

Wiktionary

1. n. An observable fact or occurrence or a kind of observable fact or occurrence.
2. n. Appearance; a perceptible aspect of something that is mutable.
3. n. A fact or event considered very unusual, curious, or astonishing by those who witness it.
4. n. A wonderful or very remarkable person or thing.
5. n. An experienced object whose constitution reflects the order and conceptual structure imposed upon it by the human mind (especially by the powers of perception and understanding).

GNU Webster's 1913

1. n. See phenomenon.
2. n. An appearance; anything visible; whatever, in matter or spirit, is apparent to, or is apprehended by, observation
3. n. That which strikes one as strange, unusual, or unaccountable; an extraordinary or very remarkable person, thing, or occurrence.

WordNet 3.0

1. n. a remarkable development
2. n. any state or process known through the senses rather than by intuition or reasoning