Consumer awareness of meat-associated health and environmental risks is increasing and motivates a shift toward consuming meat alternatives. This is also reflected in efforts invested in studying meat alternatives from the perspective of nutritional, environmental, and consumer sciences. Despite shared research interest, these studies cannot be readily compared and interpreted because there is no clear consensus on what meat alternatives are. Scholarly debates on acceptance, nutritional value, and environmental advantages of meat alternatives would benefit from a clear definition of meat alternatives. With the goal of defining meat alternatives, relevant scientific literature in the past 10 years was systematically searched and screened guided by the scoping review Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension. The initial search resulted in >100,000 hits, which was reduced to 2465 papers. Next, titles and abstracts were scrutinized using Rayyan.ai, resulting in 193 articles considered for the present review. Article screening and data extraction was performed using ATLAS.ti software. Three major themes were identified to define meat alternative products including:1) producing and sourcing of ingredients;2) product characteristics (that is, sensory characteristics, nutritional value, and health profile, social and environmental sustainability profile); and3) consumer characteristics concerning the marketing and consumption context. Meat alternatives are multifaceted, that is, certain products can be considered as meat alternatives in some context, but not in another context. For any product, it is impossible to unequivocally state that it is a meat alternative. There is a lack of consensus from the diverse literature on what constitutes meat alternatives. However, products may be qualified as meat alternatives according to three key criteria as proposed in a taxonomy:1) production and sourcing,2) product characteristics, and/or3) consumption. We recommend researchers (and other stakeholders) to do so as it allows for better informed future discussions of meat alternatives.