köken: From Old Galician-Portuguese mesmo, from earlier Old Galician-Portuguese meesmo, from Vulgar Latin of Iberia *medesmo, from proto-Romanic forms as *medessimu, from *medissimu, from *medipsimu, from Vulgar Latin *metipsimus, from a previous *metipsissīmus, derived from Latin -met (emphatic suffix) + ipse (“himself”) + -issimus (superlative suffix). Compare with Spanish mismo, French même.
zıt: εν εναντία περιπτώσει, older spelling: ἐν ἐναντίᾳ περιπτώσει
köken: A calque of French en tout cas. Katharevousa set phrase (polytonic spelling: ἐν πάσῃ περιπτώσει) with preposition ἐν (en, “in”), the feminine singular dative πάσῃ (pásēi) of πᾶς (pâs, “everyone”) & περίπτωσις (períptōsis, “encountering”) -modern περίπτωση (períptosi, “case, instance”)-.