Pronunciation: /ˈzæk.tɪv.ɪ.ti/
Noun (informal)
1. An action or series of actions performed with the confident belief that one is exhibiting a heroic or impressive demeanor (akin to Batman), while in reality appearing notably less dramatic or heroic (closer to Robin).
2. A comically
overconfident display or pursuit, often fueled by self-assurance that exceeds the actual effect.
Origin:
Early 21st century (humorous slang): from the proper name Xac, referring to a person who habitually undertakes such endeavors, plus the English suffix -activity, signifying an action or
undertaking.