What is the meaning of Hello?

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

A greeting used when answering the telephone.

A call for response if it is not clear if anyone is present or listening, or if a telephone conversation may have been disconnected.

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.

An expression of puzzlement or discovery.

"Hello!" or an equivalent greeting.

To greet with "hello".

hello, hi

a page

one side of a wall, a wall

a slap in the face

Source: wiktionary.org