hey /ˈheɪ/ interjection
— used to attract someone's attention or to express surprise, joy, or anger ▪ Hey (there), it's good to see you! ▪ Hey, wait for me! ▪ Hey, what are you doing with my car! ▪ Hey you!—get away from there!
— used to indicate that something is not important, that you are not upset about something, etc. ▪ I thought she was my friend, but, hey, it's not the first time I've been wrong. ▪ “We lost.” “Hey, you can't win them all.” ▪ “I'm sorry to be so late.” “Hey, don't worry about it.”