The first is that all of these are simply weaker or stronger nerve-deadeners; most of them actual narcotics.
Cited from Preventable Diseases, by Woods Hutchinson
On the mental side, selfishness is one of the most complete and effectual deadeners of inspiration.
Cited from Spirit and Music, by H. Ernest Hunt
To lighten or counteract such a descent, the most powerful springs, checks, rockets, screens, deadeners, even if the whole Earth were engaged in their construction -- would produce no more effect than so many spiderwebs.
Cited from All Around the Moon, by Jules Verne
Besides, most of these headache medicines, which for a time will relieve the pain of a headache, are narcotics, or pain-deadeners; and in more than very moderate doses they are poisons, and often dangerous ones.
Cited from A Handbook of Health, by Woods Hutchinson