A2
used as a way of attracting someone's attention, or as a greeting
Dictionary examples:
Hey! Your pants are on fire! (0.0)
Hey, is that a flying pizza I see? (0.0)
Hey, did you order this elephant for breakfast? (0.0)
Hey! What are you doing with my car? (14.2)
Hey, are you guys coming to Angela's party? (17.2)