Webster’s Revised Unabridged Dictionary · 1913
Soapberry tree
Soap′ber′ry tree′ (sŏp′bĕr′ry̆ trē′). (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.