Proto-Basque: *uśu
Meaning: 1 pus, matter 2 serum (of blood) 3 serous fluid 4 soreness, inflammation
Low Navarrese: (Hazparren) usu 1, 2, (Aldude) usi 4, (Garazi) usi 3
Zuberoan: üsü 2, üsi 3
Comments: A northern Bsq isogloss. Cf. PNC *ɦ[a]mʒ_ū 'saliva, mucus, herpes': Lak uInc̣u 'snot', etc..