verb

administer a drug to (someone) in order to induce stupor or insensibility.

they were drugged to keep them quiet

anaesthetize,give an anaesthetic to,narcotize,give drugs to,give narcotics to,give opiates to,poison,knock out,make/render unconscious,make/render insensible,stupefy,befuddle,dope,add drugs to,tamper with,adulterate,contaminate,spike,lace,slip a Mickey Finn into,doctor,stupefied,insensible,befuddled,delirious,hallucinating,narcotized,anaesthetized,knocked out,comatose,stoned,high,doped,dopey,on a trip,tripping,spaced out,zonked,wasted,wrecked,high as a kite,off one’s head,out of one’s mind,flying,turned on,hyped up,freaked out,charged up,loved-up,turnt,blitzed