Dictionary.com
Thesaurus.com
Jump to:
Synonyms

hi

1 American  
[hahy] / haɪ /

interjection

  1. (used as an exclamation of greeting) hello!

hi 2 American  
[hahy] / haɪ /

adjective

  1. an informal, simplified spelling of high.

    hi fidelity.
HI 3 American  

abbreviation

  1. Hawaii (approved especially for use with zip code).

  2. Meteorology. heat index. Also H.I.

H.I. 4 American  

abbreviation

  1. Hawaiian Islands.

  2. Meteorology. heat index. Also HI

HI 1 British  

abbreviation

  1. Hawaii (state)

  2. Hawaiian Islands

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
hi 2 British  
/ haɪ /

  1. an informal word for hello

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
hi 3 British  
/ haɪ /

interjection

  1. an expression used to attract attention

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of hi

First recorded in 1425–75; late Middle English hy, perhaps variant of hei hey

Explanation

Hi is a common greeting, more casual than "hello." When you walk down the street in a small town, it might seem like everyone you pass says "hi." The word hi is a good, nearly all-purpose greeting — it's appropriate in all but the most formal circumstances, so you might want to skip saying, "Hi" to the Queen when you meet her. When you greet someone, you have a lot of words to choose from, including "hey," "hello," "hiya," and "howdy," but hi is probably the most common. The first mention of hi attributes it to a Kansas native American in the 1800s.

Keep Reading on Vocabulary.com

Vocabulary lists containing hi

Scrabble: Two-Letter Words

Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!

Spelling Practice 1, Unit 3

Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

“When you’re out on a run or a walk or a bike ride, do you say hi to people that pass? If you don’t, I’m not so sure about you,” he joked.

From MarketWatch • Apr. 20, 2026

Ovitz, the former superagent, says he’ll always stop to say hi, but: “We all know: Don’t hang out.”

From The Wall Street Journal • Mar. 9, 2026

If you ever feel like grabbing a coffee or saying hi, I’d love that.

From Salon • Jan. 27, 2026

“I come up here sometimes just to say hi to him.”

From Los Angeles Times • Jan. 1, 2026

“She said to say hi when I saw you,” he told me.

From Absolutely Almost by Lisa Graff

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.