Why Do “Flammable” And “Inflammable” Mean The Same Thing?Why are these two words so confusing? Well, flammable and inflammable both mean “able to be set on fire.” Strangely, the "in" prefix in inflammable doesn't make the word mean "not flammable," as you might think.
Origin of sulfureted hydrogen
First recorded in 1795–1805
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019