in private, in confidence, one-to-one, face-to-face (occurring privately with the involvement of two people)
köken: From négy (“four”) + szem (“eye”) + közt (“between”), literally “between four eyes”. Compare French entre quatre yeux, German unter vier Augen, Italian a quattr'occhi, Polish w cztery oczy, Czech mezi čtyřma očima.
köken: From Proto-Italic *klām, perhaps an adverbial accusative from Proto-Indo-European *ḱl-eh₂- (“concealment”) from *ḱel- (“to hide, conceal”). Cognate with Latin cēlō and others.