  This paper presents a method to understand spoken Tunisian dialect based on
lexical semantic. This method takes into account the specificity of the
Tunisian dialect which has no linguistic processing tools. This method is
ontology-based which allows exploiting the ontological concepts for semantic
annotation and ontological relations for speech interpretation. This
combination increases the rate of comprehension and limits the dependence on
linguistic resources. This paper also details the process of building the
ontology used for annotation and interpretation of Tunisian dialect in the
context of speech understanding in dialogue systems for restricted domain.
