BT Er 29b(1) :לא אמרן אלא דלא אבצל זרתא אבל אבצל זרתא לית לן בה‏ : we only said it when they have not branched apart a span [lit.: a span has split]; but if they have branched apart a span we have no objection to it
See the entire entry for bṣl vb. Dt to be split

BT Er 29b(1) :לא אמרן אלא דלא אבצל זרתא אבל אבצל זרתא לית לן בה‏ : we did not say regarding the leaves (of the onion, that they are poisonous) except when they have not branched apart a span. But if they have branched apart a span there is no objection to it
See the entire entry for zreṯ, za/irtā n.f.(m.) span