adjective/ˈtɾiste/
sad, saddened, blue, gloomy, unhappy, joyless, triste; dismal, dreary, glum, miserable, melancholic; sorrowful, mournful; forlorn; upsetting, saddening
“¿Por qué estás tan triste?” — Why are you so sad?
Borrowed from Latin trīstis. Compare the Old Spanish tristo, inherited from Vulgar Latin trīstus.