Meaning

noun an expression of greeting

originHello (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…

Etymology from Wiktionary, CC BY-SA 3.0