Slang is generally considered an unconventional vocabulary characterized by connotations of novelty, informality, and even derogatoriness or offensiveness. As such, it can be used as means of social exclusion and verbal aggression. The derogatory character of slang is particularly evident in its innovatory lexicon, as well as in the metaphorical extensions of its vocabulary. This study adopts a morphopragmatic approach to analyse slang words. In particular, it focuses on the usage of the suffix -o in offensive and aggressive contexts with nefarious intent, as in the words sicko, lesbo, or commo. The study is both dictionary-driven and corpus-based. Data selected from Green’s Dictionary of Slang have been collected in order to investigate how the -o suffix is utilized in hate communication to denigrate, dehumanize, and marginalize groups or individuals. Contextualized examples from COCA are analysed from the quantitative and qualitative viewpoints with the aims to: 1) identify the genres and environments where the -o suffix finds its preferred application, 2) investigate the most common collocational patterns where slang -o words convey a pragmatic meaning [aggressive], and 3) show the specific connotational meanings/pragmatic effects contributed by the -o suffix.