The literal meaning of " koselig" is cozy, but it is used far more in Norwegian than it is in English as it can be used to describe a number of things that are nice or lovely such as spending time with friends, eating a nice meal or simply relaxing in front of the fire For example - det var en koselig dag- it was a cozy(lovely) day.

Bethan Winter's answer is good. "Koselig" together with "å kose seg" are probably the most important Norwegian words ;) Nå har vi det koselig - now, we are enjoying ourselves Det var koselig - that was nice For en koselig dame - what a nice/pleasant lady En koselig hytte - a cozy cabin En koselig film - an enjoyable, pleasant, warm movie