un·flap·pa·ble \ˌənˈflapəbəl\adjective (-es) Etymology:un- (I) + flap (II) + -able : marked by assurance and self-control : imperturbable < the most unflappable of politicians — Anthony Lewis > • un·flap·pa·bil·i·ty\-ˌflapəˈbiləd.ē\noun • un·flap·pa·bly\-ˈflapəblē\adverb