ILexicOn: toward an ECD-compliant interlingual lexical ontology described with semantic web formalisms

We are interested in bridging the world of natural language and the world of the semantic web in particular to support natural multilingual access to the web of data. In this paper we introduce a new type of lexical ontology called interlingual lexical ontology (ILexicOn), which uses semantic web formalisms to make each interlingual lexical unit class (ILUc) support the projection of its semantic decomposition on itself. After a short overview of existing lexical ontologies, we briefly introduce the semantic web formalisms we use. We then present the three layered architecture of our approach: i) the interlingual lexical meta-ontology (ILexiMOn); ii) the ILexicOn where ILUcs are formally defined; iii) the data layer. We illustrate our approach with a standalone ILexicOn, and introduce and explain a concise human-readable notation to represent ILexicOns. Finally, we show how semantic web formalisms enable the projection of a semantic decomposition on the decomposed ILUc.

💡 Research Summary

The paper addresses the persistent gap between natural language resources and the Semantic Web, with a particular focus on enabling natural multilingual access to the growing Web of Data. To this end, the authors introduce a novel type of lexical ontology called an Interlingual Lexical Ontology (ILexicOn). Unlike traditional lexical ontologies such as WordNet, BabelNet, or OntoLex‑Lemon, which are either monolingual or rely on external links for cross‑lingual alignment, ILexicOn is built directly on Semantic Web standards (RDF, RDFS, OWL, SKOS) and follows the Exact Conceptual Description (ECD) principle to guarantee logical consistency and precise conceptual modeling.

The architecture of ILexicOn is organized into three distinct layers.

1. Interlingual Lexical Meta‑Ontology (ILexiMOn) – This top‑level schema defines the core building blocks: the Interlingual Lexical Unit class (ILUc), semantic roles, and relationship types. Implemented in OWL DL, ILexiMOn encodes class hierarchies, property constraints, and ECD‑compliant axioms, thereby providing a formal foundation for all downstream layers.
2. ILexicOn (Lexical Layer) – Here the actual lexical units are instantiated as subclasses of the meta‑ontology. Each ILUc carries a human‑readable definition (via skos:definition) and, crucially, a semantic decomposition expressed through a dedicated property (e.g., ex:semanticDecomposition). The decomposition is recursive: the components of a decomposition are themselves ILUcs, allowing the ontology to be self‑referential. This design enables the projection of a unit’s meaning structure onto the unit itself, a feature the authors term “self‑projection.”
3. Data Layer – This layer connects the abstract ILUcs to concrete language data (surface forms, lexical frequencies, corpora). Instances are stored as RDF triples and linked to language‑specific literals. A SPARQL endpoint exposes the whole graph, making it possible to pose multilingual queries such as “Find all French expressions that instantiate the ILUc ‘event:Birth’.”

To make the ontology approachable for human designers, the authors propose a concise textual notation that mirrors the underlying RDF structure. For example, a decomposition can be written as `ILU:Birth →