Antonyms for inconsequentialness, which means of little or no importance, are significant, substantial, consequential, critical, crucial, weighty, momentous, paramount, and essential. These words refer to the importance, gravity, or significance of something. For instance, when something is significant, it has considerable importance, meaning or influence. On the other hand, when something is consequential, it has a significant effect or outcome. In essence, these antonyms suggest the opposite of triviality or lack of consequence. Thus, they are used to describe specific situations or events that hold great relevance, value, or import. The use of antonyms helps to provide context and contrast, enriching the language and conveying meaning more effectively.