Jastrow: מָנְפּוֹל

מָנְפּוֹל m. (μονοπώλιον) a trading mart enjoying a monopoly. Dem. V, 4 בלוקח מן המ׳ when he buys (loaves of bread) in a monopolized market (where the numbers of bakers and of retailers are limited). Y. ib. 24ᵈ top איזהו מ׳ וכ׳ what sort of a mart? Where there are nine sellers supplied by eight bakers, so that eight may have bought from one baker severally, but one baker must necessarily have supplied at least two sellers.