This is the 6773rd most frequent Russian word.
ufs
It appears "ufs" is not a standard Russian word.
The word 'Уф' is used as an interjection expressing exasperation about the heat.
Уф, какой горячий день сегодня.
Uf, what a hot day it is today.
The word 'Уф' is used as an interjection expressing shock or disappointment.
Когда я услышал плохую новость, я только смог сказать: 'Уф!'
When I heard the bad news, I could only say: 'Uf!'
The word 'Уф' is used as an interjection expressing relief from effort.