savonette
/ˈsavənɛt/ /ˌsavəˈnɛt/(also savonnette) Now rare
noun
1A ball of perfumed soap containing a powder which creates a thick lather when dissolved in water.
2 Caribbean. Any of several tropical American trees of the family Fabaceae (Leguminosae) with bark or leaves which are used as a soap substitute; specifically (in early use) Abarema macradenia (formerly Pithecolobium macradenium), and (in later use) any of several trees of the genus Lonchocarpus.
Origin
Early 18th century; earliest use found in Boccaccio's Il Decamerone. From Italian savonetta and its model French savonnette from savon soap + -ette, feminine diminutive suffix.