noun pl. phenomena -·na (-nə), phenomenons -·nons′

1. any event, circumstance, or experience that is apparent to the senses and that can be scientifically described or appraised, as an eclipse
2. in Kantian philosophy, a thing as it appears in perception as distinguished from the thing as it is in itself independent of sense experience
3. any extremely unusual or extraordinary thing or occurrence
4. Informal a person with an extraordinary quality, aptitude, etc.; prodigy

Etymology: LL phaenomenon < Gr phainomenon, neut. prp. of phainesthai, to appear, akin to phainein: see fantasy