najbliższa rodzina krewny Englisch:

In the unfortunate event of an accident, please complete your next of kin details below

The police suspect the identity of the kidnapped man, but they haven't yet informed his next of kin

When I arrived in New York, my next of kin greeted me warmly and showed me round Greenpoint.

Doctor wanted to know if I was next of kin.

I'm her next of kin.