What term describes a feeling of utter weariness and discontent resulting from satiety or lack of interest?

The term that best describes a feeling of utter weariness and discontent resulting from satiety or lack of interest is ennui. Ennui captures a profound sense of listlessness and dissatisfaction that often arises from a lack of excitement or variety in life. It is a state where an individual feels both bored and weary, usually linked to a realization of emptiness amid abundance or routine.

In contrast, boredom refers to a temporary feeling of disinterest in a specific situation or activity, lacking the depth and nuanced emotional undercurrents associated with ennui. Fatigue pertains to physical tiredness and can occur due to exertion, but it does not inherently encompass the emotional and existential aspects tied to ennui. Amusement implies a light-heartedness and enjoyment, which stands in stark contrast to the feelings of weariness and discontent associated with ennui. Thus, ennui is the most fitting term to describe this particular sentiment of existential dissatisfaction.