a greeting or exclamation
said with an exaggerated high
pitch, sass, enthusiasm and emphasis on the "haaay." Often used to indicate sexiness or a vivacious
attitude.
Mary: Wow, your hair looks great today.
Susan: You like it? I just cut it.
Mary: Oh Hay!
Susan: Oh HAAY!
Kelly: I have a date tonight
Jessica: Oh HAY!
If a girl in a bikini appears it would be proper for her to receive a chorus of "Oh HAYs" from her friends.