B / bullātĭo
noun

bullātĭo

gen. bullātōnis · gender feminine · decl. 3rd
a bubbling; forming of pebbles
a bubbling, forming of pebbles, of a stone found in small detached fragments: sparsa bullatio magnetis (opp. cautes continua), Plin. 34, 14, 42, § 148 Sill. and Jan. (al. bulbatio).