Which word best describes a feeling of weariness and dissatisfaction due to lack of interest?

The word that best describes a feeling of weariness and dissatisfaction due to lack of interest is "ennui." This term originates from the French word for boredom and encompasses a profound sense of dissatisfaction and restlessness that arises when one feels unengaged or unchallenged, often due to monotony or lack of stimulation. It captures the essence of feeling tired and discontent because of a lack of meaningful engagement in activities.

In contrast, exuberance refers to an energetic and enthusiastic state, while ecstasy is associated with intense joy or overwhelming happiness. These two words reflect positive feelings, which do not align with the notion of weariness or dissatisfaction. Exhaustion, on the other hand, indicates a physical or mental state of extreme tiredness, but it does not necessarily imply a lack of interest; rather, it frequently results from overexertion. Hence, ennui is the most fitting choice as it precisely encapsulates the feeling of weariness paired with dissatisfaction due to a lack of interest.