Two groups of terms have been gathered. The first one comes from a specialized text corpus, in which the terms are defined by the authors themselves. The second one comes from within the framework of institutional terminology (official terminology and neology committees), where terms have been selected by specialists themselves. Those two groups of terms therefore are repesentative of the specialties in question. Morphological characteristics of specialized terms have been emphasized; the variability of their discursive usages has also been highlighted.