This is the 1336th most frequent Russian word.
упала
"Упала" means "fell" in English.
The verb 'упала' is used in the past tense, feminine singular, indicating the action of falling or moving downward involuntarily.
Вдруг книга упала с полки.
Suddenly, the book fell from the shelf.
Here, 'упала' metaphorically expresses the location of the sun moving below the horizon, still in the past tense, feminine singular.
Солнце уже упало за горизонт.
The sun has already set below the horizon.
The word 'упала' describes a physical fall of a person, emphasizing an involuntary action, in past tense, feminine singular form.