The characterization and detection of social bots with their presumed ability to manipulate society on social media platforms have been subject to many research endeavors over the last decade, leaving a research gap on the impact of bots and accompanying phenomena on platform users and society. In this systematic data-driven study, we explore the users’ perception of the construct bot at a large scale, focusing on the evolution of bot accusations over time. We create and analyze a novel dataset consisting of bot accusations that have occurred on the social media platform Twitter since 2007, providing insights into the meanings and contexts of these particular communication situations. We find evidence that over time the term bot has moved away from its technical meaning to become an ‘insult’ specifically used in polarizing discussions to discredit and ultimately dehumanize the opponent.