How is "ennui" best described?

"Ennui" is best described as a feeling of boredom, particularly a profound or deep-seated type of boredom that stems from a lack of interest or engagement in one's surroundings or activities. This term often conveys a sense of dissatisfaction and weariness as a result of monotony or a lack of stimulation, making “boredom” the most fitting description. The other choices highlight emotions or states that contrast sharply with ennui; for example, a feeling of joy or heightened excitement represents a positive emotional state, while a strong sense of curiosity indicates an active engagement with the world, which is the opposite of the apathetic nature associated with ennui.