Cozy or comfy?
Icelandic has a slang word kósi which of course is a borrowing of the English term cozy. I do not know where the English term comes from exactly. Comfy, on the other hand, I know is an abbreviation of comfortable, which is a latinate.
Icelanders say when they are inviting people over to their house that people should come over and "hafa það kósi." Now in English we usually reserve cozy for when a couple is snuggled together on the couch under a blanket, or when a parent is trying to settle their child down before bedtime. That is cozy in English. I think the way Icelanders use kósi is therefore more akin to English comfy, as in the equivalent of a host saying in English, "make yourself comfy." This means to come over to the house and have a casual, comfortable evening without a lot of pretense, just relaxing and talking.