- The definition of defiant is someone or something that resists behaving or conforming to what is asked or expected.
An example of defiant is someone who is told to do something and immediately does the opposite.
A child acting defiant.
full of defiance; openly and boldly resisting
Origin of defiantFrench défiant, present participle of défier
Marked by defiance; boldly resisting.
French défiant, from the verb défier