Semantic change and socio-semantic variation: the case of COVID-related neologisms on Reddit

Abstract COVID-19 has triggered innovations in science and society globally, leading to the emergence or establishment of formal neologisms such as infodemic and working from home ( WFH ). While previous work on COVID-related lexical innovation has focused on such formal neologisms, this paper uses data from Reddit to study semantic neologisms like lockdown and mask , which have changed in meaning due to the pandemic. First, we identify words that have undergone meaning changes since the start of the pandemic. Our approach, based on word embeddings, successfully detects a variety of COVID-related terms that dominate the resulting list of semantic neologisms. Next, we generate community-specific semantic representations for the communities r/Coronavirus and r/conspiracy , which are both highly engaged in COVID-related discourse. We analyse socio-semantic variation along two dimensions: an evaluative dimension, based on amelioration/pejorization, and the loyalty/betrayal dimension of Moral Foundations Theory. Our findings reveal that the detected semantic neologisms exhibit more negative and betrayal-related associations in r/conspiracy , a subreddit critical of COVID-related sociopolitical measures. Mapping the community-specific representations for the term vaccines on a shared semantic space confirms these differences and reveals more fine-grained denotational and connotational differences between the two communities.