BT AZ 26a(40) :דשיפא לה סם בדד מאבראי וקטלא ליה‏ : (the wet nurse) rubs poison on the teat from the outside, and she kills it [i.e. the nursing child]
See the entire entry for mˀbrˀy adv. from without

BT AZ 26a(40) :דשיפא לה סם בדד מאבראי וקטלא ליה‏ : (the wet nurse) smears poison on a teat from the outside, and she kills it [i.e. the sucking child]
See the entire entry for šwp vb. to smear; grind down