1 : not responding to treatment; "a stubborn infection"; "a refractory case of acne"; "stubborn rust stains"
2 : blindly and obstinately attached to some creed or opinion and intolerant toward others; "a bigoted person"; "an outrageously bigoted point of view"
3 : obstinate and stupid
4 : haughtily stubborn; "a stiff-necked old Boston brahmin"
5 : unreasonably rigid in the face of argument or entreaty or attack
