An example of something kosher is matzoh made in Israel with a kosher logo on it.
An example of kosher is the question you ask if you aren't sure about something, "Is it kosher to bring wine to someone's house that doesn't drink?"
An example of kosher is to take a pan and wash it in a natural running body of water, like a river.
Is it kosher to wear jeans in the office?
A kosher household.
A kosher restaurant.
A kosher kitchen.