A Russian word found to have no English equivalent described by Vladimir Nabokov. I don’t think there is anything quite close to describing the anguish of restlessness and struggling with our own innate human-ness. This word brings me warmth knowing there is someone out there, who understands.
“No single word in English renders all the shades of toska. At its deepest and most painful, it is a sensation of great spiritual anguish, often without any specific cause. At less morbid levels it is a dull ache of the soul, a longing with nothing to long for, a sick pining, a vague restlessness, mental throes, yearning. In particular cases it may be the desire for somebody of something specific, nostalgia, love-sickness. At the lowest level it grades into ennui, boredom.”