Deliberate development and management of an enterprise manifests complexity that posses a key question: "How to obtain comprehensive intelligibility of an enterprise?" One conceptual tool to overcome this is Enterprise Modeling. This paper presents a proposal for a Systemic Enterprise Modeling Language, derived from propositions within a French School of Systems Science, also known as "Le Moigne's Systemics". This paper presents the proposed language?s theoretical foundations together with the derived enterprise modeling constructs or categories, such as an enterprise's Consumer, Output, Process, Organizational Culture, Rules, and Goals. This is followed by a comparison of the proposed language with other current languages for enterprise modeling, including a case study. This shows that the proposed language supports generation of the highest comprehensiveness of modelled enterprise. This is since the propose language provides a richer set of enterprise constructs.