Phenomenon

noun

1. A thing or being, event or process, perceptible through senses; or a fact or occurrence thereof.
2. (by extension) A knowable thing or event (eg by inference, especially in science)

   "An electromagnetic phenomenon."

3. A kind or type of phenomenon (sense 1 or 2)

   "A volcanic eruption is an impressive phenomenon."

4. Appearance; a perceptible aspect of something that is mutable.
5. A fact or event considered very unusual, curious, or astonishing by those who witness it.