Lewis Short
serpĕrastra | serpĭr- (noun N) : (), , perh. from serpo - rastrum, creepingsplints
* Knee-splints or knee-bandages for straightening the crooked legs of children. *
* Lit.: pueris in geniculis alligare,Varr. L. L. 9, § 11 Müll.—*
* Transf., humorously of officers, who hold the soldiers in check: de serperastris cohortis meae nihil est quod doleas,Cic. Att. 7, 3, 8.
Charlton T. Lewis, Charles Short, A Latin Dictionary