ustĭo — Lewis & Short
ustĭo, ōnis, f.uro,
I a burning, searing, or cauterizing (post-Aug. and very rare):
si costa cariosa est, inutilis ustio,Cels. 8, 2 fin.:
quaedam ustione sanantur,Plin. 34, 15, 44, § 151:
vehementior sinapis,id. 20, 22, 87, § 239.