c.1300, from O.Fr. souple "pliant, flexible," from Gallo-Romance *supples, from L. supplex (gen. supplicis) "submissive, humbly begging," lit. "bending, kneeling down," thought to be an altered form of *supplacos "humbly pleading, appeasing," from sub "under" + placare "appease" (see
placate).