Our work treats onomastics in the lower part of the Adour river broadly speaking in the Bayonne region and is based, in particular, on thousands of notaries' minutes which are so far very often unexploited ; i.e. it notably encompasses sciences such as toponymy in rural areas or towns, anthroponymy, hydronomy and oronymy of one part of the littoral section of the Labourd province at a transition period, the XVIIIth century, mainly marked by the decline of the popular Basque culture and in towns by tremendous upheavals that will spread headlong to the whole region of Bayonne-Anglet-Biarritz during the XIXth and the XXeth centuries.