Bekhorot 22: words to know

בִּיטּוּל בְּרוֹב (bittul berov): Halakhic nullification of a minority within a majority. Rabbi Yoḥanan explains that the expelled fetus does not impart impurity because it is nullified in the larger mass.
עַם הָאָרֶץ (am ha'aretz): One not trusted regarding the laws of ritual purity. Fish brine purchased from an am ha'aretz requires a procedure to ensure it is ritually pure.
מִמָּה נַפְשָׁךְ (mimah nafsheikh): Whichever way you look at it; in either case. Reish Lakish uses this formula to argue that the brine is ritually pure under either possible scenario.
הַשָּׁקָה (hashakah): Purification of water by touching a ritual bath. The Gemara states that bringing the water mixture into contact with a mikveh purifies the water.
חָזְרָה וְנֵיעוֹרָה (ḥazra veni'ora): Reawakens after having been previously nullified. Abaye questions the premise that a substance whose impurity was nullified can become impure again upon contacting its own kind.