Hi
Part of speech: interjection
Definition: A friendly, informal, casual greeting said when meeting someone.
Part of speech: adjective
Definition: , often hyphenated.
Example sentence: I marketed pens - on the phone. But the beauty of the gig was that you had to call these strangers and say, 'Hi, how ya doing?' You made up a name, like, 'Hey, it's Edward Quartermaine from California. You're eligible to receive this grandfather clock or a trip to Tahiti.' You promise them all these things if they buy a gross of pens.
Hullo
Part of speech: interjection
Definition: A greeting (salutation) said when meeting someone or acknowledging someone’s arrival or presence.