οὐ γάρ ἐστινplugin-autotooltip__default plugin-autotooltip_bigεἰμί

greek

εἰμί is the first person singular verb for “to be” (εἶναι [the infinitive form] = “to be”).

It an irregular verb, and, like English, changes significantly between person and tense. For example εἰμί is the word for am and ἦν is the word for was, e.g.
ἀνὴρ ἐκ γυναικός, ἀλλὰ γυνὴ ἐξ ἀνδρός·