What term describes a lack of interest or concern?

The term that describes a lack of interest or concern is apathy. When someone is apathetic, they exhibit indifference or a lack of enthusiasm towards situations or issues that typically might evoke a response or emotional involvement. This can manifest in various areas of life, including civic engagement, where a lack of interest in community affairs or social issues can hinder participation and impact.

In contrast, the other terms represent opposite states of being: engagement refers to active participation or involvement, curiosity denotes a desire to learn or know more about something, and enthusiasm reflects eagerness and excitement.