- Borrel could be translated as drinks. Usually there will be small snacks as well, but that often goes together with drinks as well.
- Gezellig is not just cosiness. If that was it, there'd be an English word right?
- Gunnen is the only one, besides gezellig, that seems to really not exist. Gezellig is rather famous for it because it's difficult to translate. Gunnen on the other hand can easily be described with other words: "ik gun het je" ("I 'gun' it [to] you") would be "I'd like for you to have it" (e.g. the last piece of cake).
- I never heard of Janteloven or anything similar. Turns out it doesn't exist: http://www.woorden.org/woord/janteloven
- Queesting does not exist, either. I never heard of that.
- Lekker is tasty or nice depending on context. It has different meanings in different contexts, but that doesn't mean there is no translation. It doesn't mean all of the possible contextual translations at the same time.
- Uitwaaien is getting some fresh air.