flammable / inflammable
Two words that both mean easy to burn.
Flammable and inflammable mean the same thing: easy to catch fire. Nonflammable is the opposite. Prefer flammable on a warning. Inflammable is often misread as “will not burn.”
Examples
Useflammable liquid
Usenonflammable cloth
Avoidinflammable liquid (If a reader might take in- as not.)