In Hindi, "Phuks" translates to "Foux", which is a French word.
The word "Foux" is an obsolete form of "Fous".
In Czech, "Fous" means "Whisker".
From Wiktionary:
The spelling fous is a colloquial spelling of the more common vous. It is only used in the expression "o fous" meaning "by a whisker"
I thought it was because of the German word "Fuchs", which translates to fox.