BT Ḥul 48a(9) :סכינא דחליש פומיה‏ : a knife whose blade is dull
See the entire entry for ḥălīš adj. weakened, powerless

BT Ḥul 48a(9) :מייתי׳ סכינא דחליש פומיה ומפריקנא ליה‏ : I shall bring a knife whose blade is thin and will separate it
See the entire entry for prq vb. to redeem; to dismantle