This is the 1997th most frequent Russian word.
тысячу
"Тысячу" means "thousand" (accusative case in Russian).
The word 'тысячу' is used here in the accusative case as the direct object of the verb 'потратил', indicating the amount of money spent.
Я потратил тысячу рублей на продукты.
I spent a thousand rubles on groceries.
In this sentence, 'тысячу' is used figuratively in the accusative case to express gratitude in a lofty manner.
Тысячу спасибо за помощь!
A thousand thanks for your help!
Here, 'тысячу' is used in the accusative case as a quantifier of the noun 'историй', indicating the approximate count of stories told.