On

Part of speech: preposition, adverb, adjective

Definitions

1. Resting upon or touching a surface ; running or switched into operation ; moving ahead and continuing ; concerning a subject ; happening at a set time
2. Supported by a surface or in contact with it ; active or powered up ; progressing further along a path ; regarding a topic ; scheduled for a given day or moment
3. Lying atop something ; working or turned to the active state ; forward in progress ; about a certain matter ; taking place at a particular hour or date

Etymology: The English word "on" is one of the oldest words in the language, and its earliest form, "an", meant "on, upon, onto, in, into" all at once. Its ancestry runs back to a Proto-Indo-European root meaning "on, onto," and its close relatives survive across Germanic and Slavic languages: German "an," Dutch "aan," Swedish "å," and Russian "на" (na), which all share the sense "on" or "at." Because so many languages preserve this same small word, it is a reliable marker of a shared ancestry that predates recorded history. A second, unrelated "on" also exists in English, borrowed from Japanese. In Japanese, "on'yomi" (音読み) means "sound reading," the way a Chinese character is pronounced when it was borrowed into Japanese. English speakers adopted "on" as a term for that reading, so the same spelling covers two words with completely different histories.

Synonyms: upon, atop, onto

Antonyms: off