Apartment and Co-op

Apartment noun - A room or set of rooms in a private house or a block used as a separate dwelling place.

Co-op and apartment are semantically related In some cases you can use "Co-op" instead a noun "Apartment".

Co-op noun - A jointly owned commercial enterprise (usually organized by farmers or consumers) that produces and distributes goods and services and is run for the benefit of its owners.

Apartment and co-op are semantically related in protection topic. You can use "Apartment" instead a noun phrase "Co-op", if it concerns topics such as human habitat, place for living, place where a human lives, place where someone resides.