obdurate
adj.
mid-15c., "stubborn; hardened," from Latin obduratus "hardened," past participle of obdurare "be hard, hold out, persist, endure," from ob "against" (see ob-) + durare "harden, render hard," from durus "hard" (see endure). Related: Obdurately.
〔李〕[ob-;dur;-atea.] a.顽固不化的； 倔强的 ←dur (L durare)=to harden or last 使坚固； 持久