Applying established definitions of bullying to the more recent phenomenon of cyberbullying often results in an ill-fitting definition which is contested by academics. There are particular difficulties when applying the well-documented facets of intentional harm, repetition and power imbalance to the context of online bullying. A contested definition presents challenges when comparing studies and for building theory. This qualitative study investigates defining characteristics of cyberbullying, drawing on the lived experiences of young people (aged 11-17 years) situated in the north west of England. Young people's experiences point to a more nuanced experience with different characteristics incorporating: the intention to harm or humiliate; that the victim cannot escape from the activities perpetrated against them; an attempt to transfer power from the victim; and the perpetrator hides behind the screen.