Bekhorot 38: words to know

כְּלִי שֶׁטֶף (keli shetef): a vessel purified through rinsing or immersion. Contrasted with earthenware vessels regarding how susceptibility to ritual impurity applies to its exterior.
הֶיכֵּירָא (hekeira): a recognizable distinction or indicator. The Sages created a halakhic distinction so people would not mistakenly burn sacred items.
אִיבַּעְיָא לְהוּ (ibaya lehu): a dilemma was raised by them. Introduces an inquiry asking whether two animal eye conditions in the mishna are identical.
מוּם קָבוּעַ (mum kavua): a permanent blemish. Identifies an eye deformity that permits slaughtering a firstborn animal outside the Temple.
חַסּוֹרֵי מִיחַסְּרָא (chasorei mechasra): the text is incomplete and should read. Used to resolve an apparent contradiction by supplying omitted words in the mishna.