Toska (Russian)

The Russian word toska can be roughly translated to mean sadness or mournfulness. There are many shades of toska. At its lower levels, it represents ennui, a vague restlessness, or a dull ache of the soul.

More acutely it can describe a strong yearning with nothing to yearn for. In particular cases, it may be the desire for somebody or something specific, a sick pining.

At its deepest, it refers to a sensation of great spiritual anguish, often without a specific cause