Well, I just had one of those delightful moments when you spot a certain word in X language and something about it makes you feel almost sure it's not a native one, and what's more, you feel you know exactly where it comes from.
But then it gets less and less delightful, and more and more tantalizing... ...until you get confirmation of some sort, naturally.
And that's precisely what I seek here. The word? "кайф"! According to my beloved Kovalev, it's a slang term for "pleasure" or "whim", and having recently come across Hebrew "כיף" (another slangy word meaning "fun" or "pleasure" and pronounced "kef") which is definitely of Arabic origin, I can't shake off the feeling this one may just have the same roots.
Could anyone be kind enough to either confirm or refute this?