οἴσειν (oisein)
οἴσειν is an Ancient Greek form of φέρω, meaning “to carry, bring, bear”. It is the future active infinitive.
Found 46 times in the Ancient Greek texts on Socratos.
Where it is used
Thucydides, History of the Peloponnesian War 1.127.2: οὐ μέντοι τοσοῦτον ἤλπιζον παθεῖν ἂν αὐτὸν τοῦτο ὅσον διαβολὴν οἴσειν αὐτῷ πρὸς τὴν πόλιν ὡς καὶ διὰ τὴν ἐκείνου ξυμφορὰν τὸ μέρος ἔσται ὁ πόλεμος.
All forms of φέρω (conjugation table)
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.