What do these words have in common?

Wi-Fi

SOS

Idaho

Zumba

Ginsu

Kpdak

Halitosis

Corinthian leather

If my guess (based on knowledge of exactly two of them) is correct I think you could probably add Kwanzaa.

I don’t know.

I

quote:

f my guess (based on knowledge of exactly two of them) is correct I think you could probably add Kwanzaa.

You may be on the right track.

All I can think of is that Idaho, zumba, ginsu and kodak are words made of whole cloth, with no etymons. But the others are not.

I don't know. A hint?