Hi Definition

interjection
Used to express greeting.
American Heritage
Hello.
Webster's New World

A friendly, informal, casual greeting said when meeting someone.

Hi, how are you?
I just dropped by to say “hi”.
Wiktionary

An exclamation to call attention.

Wiktionary
abbreviation
Hawaii.
Webster's New World
High intensity.
American Heritage
Humidity index.
American Heritage

Hawaii, a state of the United States of America.

Wiktionary
adjective
Webster's New World

Informal spelling of high, often hyphenated.

Get hi-quality videos here!
Next, set the burner to hi.
Wiktionary
noun
"Hi" or similar greeting.
Wiktionary

Origin of Hi

  • American English (first recorded reference is to speech of a Kansas Indian), originally to attract attention, probably a variant of Middle English hy, hey (circa 1475) also an exclamation to call attention.

    From Wiktionary