Soapberry tree \Soap"ber`ry tree`\ (Bot.) Any tree of the genus {Sapindus}, esp. {Sapindus saponaria}, the fleshy part of whose fruit is used instead of soap in washing linen; -- also called {soap tree}.
soapberry tree n : a tree of the genus Sapindus whose fruit is rich in saponin [syn: {soapberry}]