hyperthyrum
From LSJ
φύγωμεν οὖν τὴν συνήθειαν ... ἄγχει τὸν ἄνθρωπον, τῆς ἀληθείας ἀποτρέπει → so let's stay away from the habitual ... it strangles us, turns us away from the truth
hyperthyrum: i, n., = ὑπέρθυρον,
I the lintel of a door-way, Vitr. 4, 6 dub. (al. hypothyrum).