An Etymological Dictionary of Astronomy and Astrophysics

1. An occurrence, circumstance, or fact, in matter or spirit, which can be perceived by human senses. → physical phenomenon.
   

2. Philosophy: For Kant, a thing as it is apprehended by the human senses as distinguished from a noumenon, or thing-in-itself.

Etymology (EN): From L.L. phænomenon, from Gk. phainomenon “that which appears or is seen,” from phainesthai “to appear,” passive of phainein “to bring to light; to show,” from PIE base *bhhā- “to shine;” cf. Skt. bhāati “shines, glitters;” Av. bā- “to shine, appear, seem,” bāmya- “light, luminous, bright,” bānu- “light, ray;” Mid.Pers. bâm “beam of light, splendor,” bâmik “brilliant,”
bâmdâd “morning, dawn.”

Etymology (PE): Padidé, noun from padid “manifest, evident, conspicuous, in sight,” variant padidâr, from Mid.Pers. pad didâr “visible,” from pad “to, at, for, in,” evolved to bé “to; for; in; on; with; by” in Mod.Pers. (O.Pers. paity; Av. paiti “to, toward, in, at;” cf. Skt. práti, Gk. poti)

• did past stem of didan “to see, regard, catch sight of, contemplate, experience” (O.Pers. dī- “to see;” Av. dā(y)- “to see,” didāti “sees;” cf.
  Skt. dhī- “to perceive, think, ponder; thought, reflection, meditation,” dādhye; Gk. dedorka “have seen”).