The word "phenomenon" comes from the Greek word φαίνεσθαι (phainesthai), meaning "to appear" or "to show."

Here's a breakdown:

* phainomenon (φαινόμενον): This is the Greek noun form, meaning "that which appears" or "appearance."

* phenomenon (Latin): The word was adopted into Latin, where it took the form "phaenomenon."

* phenomenon (English): The word entered English from Latin, and it has been used since the 16th century.

The word's origin reflects its core meaning: something that is observable or apparent, something that can be seen, heard, or experienced.