this means the act of greeting someone
Dave: Hello Mark
Mark: Hi Dave
A famous cereal based off of hell but in shapes of o's therefore Hell-o(Cereal may cause the melting of tongue, going to hell, becoming Satan but without powers, becoming a protagonist in a shitty Netflix movie, and DEATH).
Guy 1: Dude I love hellos they're so tasty!
Guy 2: Ikr
Guy 3: *Dies from eating hellos*
Guy 2 and 1: Hello, dude are you there?
Guy 3: *Cries in dead*