In MDE resolving pragmatic issues related to the management of models is key to success. Model comparison is one of the most challenging operations playing a central role in a wide range of modelling activities including model versioning, evolution and even collaborative and distributed specification of models. Over the last decade, several syntactic methods have been proposed to compare models even though they struggle in achieving higher levels of accuracy especially when the semantics of the application domain has to be considered. Existing methods improve comparison precision at the price of high performance costs. This paper discusses a lightweight semantic comparison method, which relies on a new matching algorithm that considers ontological information encoded in the WordNet lexical database further than ordinary syntactical and structural correlations. The approach has been implemented as extension of EMFCompare and evaluated to measure its precision and performances when compared to existing approaches.