A rhyming negative exclamation or description, simply meaning "dire". From The popular British Actor Danny Dyer, star of Human Traffic and Severance to name but two.
Person A: Alright Dave, how was the concert last night?
Person B: Danny Dire Mate! Thats the last time I'm going to see Barry Manilow, you mark my words!
Person A: Why the Long Face?
Person B: My Cat just died.
Person A: Thats Dire Mate, Danny Dire.