Proto-Basque: *borc / *bośt
Meaning: five
Bizkaian: bost
Gipuzkoan: bost
High Navarrese: (South) bortz, (North) bost, (Lezaka) borz
Low Navarrese: bost, (Garazi) bortz
Salazarese: bortz
Lapurdian: bortz
Baztanese: borz
Aezkoan: bortz
Zuberoan: bost
Roncalese: bost, bortz, (Ustárroz) borz
Comments: *borc and *bośt seem to reflect original allomorphs: *borc in final position and *bośt before an affix? Cf. the variation of -rc- vs. -śt- in *ɦerce ~ *ɦeśte 'intestine', and a few other cases.
