ὑπέρθυρον
From LSJ
Ἓν οἶδα, ὅτι οὐδὲν οἶδα → I know only one thing, that I know nothing | all I know is that I know nothing.
English (LSJ)
τό, = ὑπερθύριον (lintel, lintel of a door or lintel of a gate).
Greek Monotonic
ὑπέρθῠρον: τό, = το προηγ., σε Ηρόδ.
Russian (Dvoretsky)
ὑπέρθῠρον: τό верхний дверной брус, притолока Her., Arst., Plut.