This is the 4623rd most frequent Russian word.
десятилетия
"Decades."
In this sentence, 'десятилетия' is used to indicate periods of ten years, emphasizing the time span during which the changes occurred.
За последние десятилетия мир сильно изменился.
Over the last decades, the world has changed significantly.
Here, 'десятилетия' represents future periods of ten years, underscoring the long-term impact of his work.
Его работа оставит след на десятилетия вперед.
His work will leave a mark for decades ahead.
In this sentence, 'десятилетия' points to past intervals of ten years, describing the prolonged duration of the unresolved issue.