a word that typically is said after somthing impressive or remarkable has been stated. Usually something funny or witty.
what some might describe as a "high five moment"
it usually means - to emphasize the last thing you said.
buti it can also be used for no reason at all just to get some attention.
"i just totally shot this guys head off".."heyoo"
"You know that look women get when they want sex?"
(someone waving in the backround shouting):"heyoo!"
Pronounced "hey- Oh" used when a attractive person is caught by the eye, one yells heyoo to show their excitement in the person.
yo cheack that girl. heyoo!