Hello is defined as a greeting or a response when on the phone, used to bring attention or an expression of surprise.
(interjection)See hello in Webster's New World College Dictionary
interjection
Origin: var. of hollo
noun pl. hellos
See hello in American Heritage Dictionary 4
interjection
Origin:
Origin: Alteration of hallo
Origin: , alteration of obsolete holla, stop!
Origin: , perhaps from Old French hola
Origin: : ho, ho!
Origin: + la, there (from Latin illāc, that way)
.Learn more about hello