What does "defiantly" most nearly mean?

The term "defiantly" conveys a sense of resistance or bold disobedience, suggesting a firm refusal to conform or comply with authority or expectations. The word that aligns most closely with this meaning is "obstinate," which describes a stubbornness or persistence in one's opinions or actions, especially in the face of opposition or challenge. This quality of being resolute and unyielding is what connects the two terms, making "obstinate" the most appropriate synonym.

In contrast, the other options do not capture the essence of "defiantly." "Malleable" refers to something that can be easily shaped or influenced, which is antithetical to the notion of defiance. "Victorious" suggests a sense of winning or achieving success, which does not align with the rebellious connotations of "defiantly." "Certain" indicates a state of being sure or confident, lacking any implication of resistance or defiance. Thus, "obstinate" accurately reflects the spirit of defiance described in the original term.