There is a general consistency across the research literature regarding the definition of bullying. This has filtered down into the construction of governmental and school anti-bullying policies around the world. However, research suggests that children and adolescents are failing to accurately identify cases of bullying. This in turn has implications upon the accuracy of our perception of the extent of the problem of bullying within schools. The current study aimed to investigate how 11–17 year olds understand and differentiate between terms relating to interpersonal peer aggression, violence and bullying. Fifty-seven (twenty male, thirty-seven female) participants were recruited via an opportunity sample. Participants took part in focus group interviews within which they were asked to provide a definition for a list of words relating to both traditional and cyber forms of aggression, bullying and violence. Thematic analysis revealed that the participants held a shared understanding of the terms relating to aggression, bullying and violence. Participants defined each term by describing the behaviors involved, their perception of the level of control the perpetrators of each type of negative peer interaction have and the perception of those involved. The implications of these findings for both policy and future research are discussed.