When developing domain ontologies as a means to formally represent expert knowledge, the natural language definitions of the ontology terms they encompass play a crucial role for human ontology users. On the one hand, they should reflect the scientific consensus about the concepts they describe. On the other hand, "[g]ood definitions allow for non-experts and experts in adjacent disciplines to understand unfamiliar terms making it possible to confidently use terms from external ontologies, facilitating data integration." To be able to judge whether a definition is legitimate, knowing the source from which the definition was derived is also important. Thus, one of the best practices is to provide a definition source. Furthermore, doing so allows ontology users to obtain further contextual information and provides a greater chance of interpreting the definition and using the term it defines as intended. When there is no source, the user must trust the term and/or ontology creator's expertise and work with what is provided. This can lead to misunderstandings and misuse, when the definition is not clear enough, or more importantly when the same technical terms are used differently in different scientific contexts.