sonderlament
noun
The bittersweet sensation of meeting someone who feels like a once-in-a-lifetime match, only to recognize, over time, that the relationship is fraught with obstacles you can't overcome, leading to a gentle but inevitable drift apart.
From German 'sonder' (special, unique) and Latin 'lamentum' (wailing, lament), indicating a unique personal sorrow. Pronounced "SON-der-luh-ment"
