phlebotomy (n.)

"blood-letting," c. 1400, flebotomye, fleobotomie, from Old French flebotomie (13c., Modern French phlébotomie) and directly from Medieval Latin phlebotomia, from Greek phlebotomia "blood-letting," from phlebotomos "opening veins," from phleps (genitive phlebos) "a vein" (a word of uncertain origin) + tomē "a cutting" (from PIE root *tem- "to cut").