The Environment is a vast interdisciplinary field of knowledge that comprises a wide range of specialized fields such as Biology, Agriculture, Meteorology, Energy Engineering, etc. As a result, specialized concepts can have different dimensions, depending on the context of activation. In EcoLexicon (a multimodal terminological knowledge base on the Environment), concepts are categorized, according to potential scenarios of activation. Not surprisingly, this has a direct effect on concept definitions, which are regarded as mini-knowledge representations that translate part of a conceptual system into natural language (Faber, 2002). In this presentation, we focus on how multidimensionality can be accounted for and managed in natural-language definitions in EcoLexicon.