an observable fact or event
an object of sense perception rather than of thought or intuition
a fact or event that can be scientifically described and explained
a notable or remarkable circumstance or occurrence
The precision with which those accustomed to watchfulness … sleep, is not the least of the phenomena of our mysterious being. The head is no sooner on the pillow than consciousness is lost — J Fenimore Cooper
(pl usu phenomenons) an exceptional, unusual, or abnormal person, thing, or event; a prodigy
[via late Latin from Greek phainomenon, from phainomenos, present part. of phainesthai to appear]