This is the 6096th most frequent Russian word.
спуститься
"Спуститься" means "to go down" or "to descend."
Action of descending, here physically descending using stairs.
Я спустился по лестнице вниз.
I went down the stairs.
Usage describing a figurative descent, in this case the sun setting.
Солнце начало спускаться за горизонт.
The sun started to descend below the horizon.
Suggests movement to a lower physical or conceptual level.