arm-pit
From LSJ
κρατίστην εἶναι δημοκρατίαν τὴν μήτε πλουσίους ἄγαν μήτε πένητας ἔχουσαν πολίτας → the best democracy is that in which the citizens are neither very rich nor very poor (Thales/Plutarch)
under the arm-pit: Ar. and P. ὑπὸ μάλης (Plato).