What term describes a state of deep sadness or depression?

The term that best describes a state of deep sadness or depression is "melancholy." This word specifically conveys a profound and pervasive sense of sadness that extends beyond mere temporary feelings of sorrow, often implying a deeper, more contemplative sadness that can be long-lasting. Melancholy is frequently associated with a reflective or sorrowful state of mind, capturing an emotional depth that aligns closely with a lasting experience of depression.

While other terms like "gloomy," "despondent," and "dispirited" also relate to sadness and a lack of hope or energy, they do not fully encapsulate the same depth and resonance as "melancholy." "Gloomy" refers more to an atmospheric quality or a general mood rather than a deep emotional state. "Despondent" indicates a feeling of hopelessness that can accompany sorrow, while "dispirited" suggests a loss of enthusiasm or morale, usually in a more temporary sense. Thus, "melancholy" stands out as the most accurate representation of a profound, enduring sadness or depression.