This is the 1021st most frequent Polish word.
kamiński
"Kamiński" is a Polish surname derived from "kamień," meaning "stone."
The word "Kamiński" here is used as a proper noun, specifically as a surname to address someone formally.
Pan Kamiński jest bardzo miły.
Mr. Kamiński is very kind.
The word "Kamińskich" is the plural genitive form of the surname "Kamiński," referring to the family of people with this surname.
Rodzina Kamińskich mieszka na wsi.
The Kamiński family lives in the countryside.
Here, "Kamiński" is used as a proper noun in nominative case to refer to a person with this surname.