a knife with a sharp point and two sharp edges, used by doctors for cutting skin, muscle, flesh, etc. （医生手术用的）柳叶刀，小刀 A small needle or lancet is used to prick the finger so that a drop of blood can be collected and analysed. 用一根小针或刺血针刺破手指，以便可以收集和分析一滴血。
Word Originlate Middle English (also denoting a small lance): from Old French lancette, diminutive of lance ‘a lance’.