I’ve usually translated it to “cozy” with a bit of “at ease” and “comfortable”. But, I’m an American that speaks some Dutch (all my family are from the Netherlands, but I’m born in USA), so I’m not completely fluent.
Belgian (Flemish) that speaks English. I feel that those have pretty similar meanings. Gezellig can be used when talking about groups of people though, but not sure if it is used often in that context.
