Meaning

• An exclamation to get attention.

  "Hey! Listen!"

• A protest or reprimand.

  "Hey! Stop that!"

• An expression of surprise.

  "Hey! This is new!"

• An informal greeting, similar to hi.

  "Hey! How's it going?"

• A request for repetition or explanation; an expression of confusion.

  "Hey? How's that?"

• A meaningless beat marker or extra, filler syllable in song lyrics.

  "The chorus is "nana na na, nana na na hey hey hey, goodbye"."