Synonyms to impervious

anesthetic, Mickey Finn, Pentothal, alleviating, alleviative, analgesic, anodyne, assuasive, balmy, balsamic, benumbing, cathartic, chloroform, cleansing, cocaine, deadening, demulcent, dope, drug, dull, dulling, easing, emollient, ether, ethyl chloride, ethylene, gas, hard, hypnotic, impassible, impenetrable, impermeable, insensate, insensitive, knockout drop, lenitive, lullaby, mandrake, menthol, mitigating, mitigative, morphia, morphine, narcotic, nightcap, nitrous oxide, numbing, obtuse, opiate, opium, pain-killer, pain-killing, palliative, poppy, purgative, relieving, remedial, rocky, sedative, sleep-bringer, sleep-inducer, sleep-producer, sleeping pill, softening, somnifacient, soothing, soporific, stunning, stupefying, subduing, tranquilizer, obstinate, adamant, adherent, adhesive, adversary, adversative, adverse, alien, antagonistic, anti, antipathetic, antithetic, assiduous, balking, balky, beefy, bigoted, bloody-minded, bouncing, bound, bound and determined, bulldogged, bulldoggish, bulldoggy, bulletheaded, bullheaded, case-hardened, clashing, clingy, closed to, closed-minded, committed, c