It is no secret that the English language is tricky. First there is the issue of words like “then” and “than”: two words that sound the same, but are spelled differently and have completely different meanings. Or the case of “read,” and “read,” whereby, depending on the context can mean the present tense or past tense of the same verb. And then there is the issue of words like “flammable,” and “inflammable.” These two words seem like they should be opposites, when they actually mean the same thing.
Definition – Flammable vs Inflammable
As specified in the Merriam Webster Dictionary, flammable and inflammable are both defined as “capable of being easily ignited and of burning quickly.” Often used interchangeably, they are synonyms of the word combustible, and are used to refer to objects and materials.
Understanding the Root Word
While this formal definition is accepted, it doesn’t address the inherent confusion between the two, and why they mean the same thing. Perhaps the confusion comes from the root word. In the word “flammable,” the root word is flame, regularly understood as affiliated with fire. In the case of “inflammable,” however, the root word is “inflame,” which also is affiliated with fire and setting something alight. Broken down like this, without the suffix on the end, “flame,” and “inflame,” have the same meaning.
Interpreting the words this way is in contrast to interpreting “inflammable” as the word flammable with the “in” prefix attached. The prefix “in,” as used for example, in words such as “inactive,” or “inconclusive,” usually means “not.” In the case of the two words in question however, this is not the case, as the history of the word has Latin roots, stemming from the Latin verb inflmmare. Keeping things extra confusing, this Latin origin does combine the prefix “in,” meaning “to cause to,” as well as “flammare,” which means “to catch fire.” In other words, we’re combining two languages, two root words, and two prefixes, which aren’t necessarily acting as prefixes in this case. Confused yet? But confusion or not, using these words in the English language means you are making the same statement: “capable of being ignited.”
To settle settle the flammable vs inflammable issue, remember that you can indeed use both words. However, the instinctive confusion between the two has led to an increased occurrence of the word non-flammable, a word created to denote the opposite of flammable, avoiding the issue of inflammable altogether. If you want to keep things clear and avoid any misunderstanding, use flammable when you are referring to something that catches fire easily and burns, and non-flammable when you are referring to something that is the opposite.