Hair hangover /hɛː haŋəʊvə/ plural: hair hangovers. Definition; when your hair's partied too hard and is at breaking point. Solution: Chill. Our collection of Hair Masks was made for this. They'll bring hair back from the depths of despare. These little Aussie miracle workers are infused with a blend of Australian superfood ingredients that've survived the harshest conditions. So, they know what's up. Just watch those tresses bounce back to life.