ὁμολογητέον
From LSJ
τὸ ἓν καὶ τὸ ὂν πολλαχῶς λέγεται → the term being and the term one are used in many ways, one and being have various meanings, one and being have many senses
English (LSJ)
A one must allow, Pl.Ti.52a, etc.
Greek (Liddell-Scott)
ὁμολογητέον: ῥημ. ἐπίθ. τοῦ ὁμολογῶ, δεῖ ὁμολογεῖν, Πλάτ. Τίμ. 51Ε, κ. ἀλλ.