catheter (n.)

"tubular instrument inserted to draw off urine from the bladder," c. 1600, from French cathéter, from Late Latin catheter "a catheter," from Greek katheter "surgical catheter," literally "anything let down," from stem of kathienai "to let down, thrust in," from kata "down" (see cata-) + stem of hienai "to send" (from PIE root *ye- "to throw, impel").

Earlier was cathirum (early 15c.), directly from Medieval Latin; in this sense Middle English also had argalia, via Medieval Latin from Arabic. Related: Catheterization; catheterized; catheterizing.