hello

/hɛˈloʊ/

hello means A greeting (salutation) said when meeting someone or acknowledging someone’s arrival or presence.

hello is pronounced /hɛˈloʊ/.

Etymology

First attested in 1826. From holla, hollo (attested 1588). This variant of hallo is often credited to Thomas Edison as a coinage for telephone use, but its appearance in print predates the invention of the telephone by several decades. Ultimately from a variant of Old English ēalā, such as hēlā, which was used colloquially at the time similarly to how hey and (in some dialects) hi are used nowadays. Thus, equivalent to a compound of hey and lo. Used when drawing attention to yourself. Possibly influenced by Old Saxon halo, imperative of halōn (“to call, fetch”), used in hailing a ferryman, akin to Old High German hala, hola!, imperative forms of halōn, holōn (“to fetch”). For more information, see hallo. The Oxford English Dictionary and Merriam-Webster Dictionary also suggested that it is

intj

A greeting (salutation) said when meeting someone or acknowledging someone’s arrival or presence.e.g.“Hello, everyone.”
A greeting used when answering the telephone.e.g.“Hello? How may I help you?”
A call for response if it is not clear if anyone is present or listening, or if a telephone conversation may have been disconnected.e.g.“Hello? Is anyone there?”
Used sarcastically to imply that the person addressed has done something the speaker considers to be foolish, or missed something that should have been obvious.e.g.“You just tried to start your car with your cell phone. Hello?”
An expression of puzzlement or discovery.e.g.“Hello! What’s going on here?”

noun

"Hello!" or an equivalent greeting.e.g.“They gave each other a quick hello when they met, and went back on their merry ways.”

verb

To greet (someone) with "hello".e.g.“She is there guarding and looking after the candy and the children generally, and she helloes and renders an exclamation that Maidie is crossing the street.” — 1891, Records and Briefs in Cases Decided by the Supreme Court of Minnesota, page 227:

Definitions & examples from Wiktionary (CC BY-SA 3.0).