[im.preg.na.ble] adj [ME imprenable, fr. MF, fr. in- + prenable vulnerable to capture, fr. prendre to take--more at prize] (15c) 1: incapable of being taken by assault: unconquerable
2: unassailable; also: impenetrable -- im.preg.na.bil.i.ty n -- im.preg.na.ble.ness n -- im.preg.na.bly adv