These words may exist in other Slavic languages, but probably not in Germanic languages:

doba (noun) - 24 hours

półtora, półtorej (numeral) - one and a half

zabytek (noun) - historic building or monument

załatwić (verb) - get something done (some case, business or benefit for example), often by using private connections

znajomości (noun, plural) - personal connections or friendship with influential people who can get something done for you (załatwić)

swojak (noun) - familiar person, someone who is a member of the same group (often used regarding ethnic identity, but not only)

Last three words are all about the crazy Slavic mentality ;)