εἶθʼ (eith)
εἶθʼ is an Ancient Greek form of εἶτα, meaning “then, next, afterwards”. It is the adverb.
It can also be a form of εἴτε, “whether, or (εἴτε … εἴτε: whether … or)”.
It can also be a form of εἴθε, “if only!”.
Found 700 times in the Ancient Greek texts on Socratos.
Where it is used
Apollonius Rhodius, Argonautica 2.46: πειράζων, εἴθʼ ὡς πρὶν ἐυτρόχαλοι φορέονται,
Diogenes Laertius, Vitae philosophorum 2.5.47: … ιππος. λεκτέον δὲ πρῶτον περὶ Ξενοφῶντος, εἶτα περὶ Ἀντισθένους ἐν τοῖς κυνικοῖς, ἔπειτα περὶ τῶν Σωκρατικῶν, εἶθʼ οὕτω περὶ Πλάτωνος, ἐπεὶ κατάρχει τῶν δέκα αἱρέσεων καὶ τὴν πρώτην Ἀκαδημείαν αὐτὸς συνεστήσατο. ἡ μὲν οὖν ἀκ …
Euripides, Alcestis 455: εἴθ’ ἐπ’ ἐμοὶ μὲν εἴη,
Source: Socratos (socratos.org), a free reader for Ancient Greek and Latin. Grammar from the Perseus Treebank and Morpheus; dictionary entries from Liddell-Scott-Jones, A Greek-English Lexicon (Perseus Digital Library, CC BY-SA). Counts are from the texts on Socratos.