Gemütlichkeit
(pronounced /gəˈmyːtlɪçkaɪt/) is a German abstract noun whose closest English equivalent is cosiness. However, rather than basically just describing a place as not too large, well-heated and nicely furnished (a cosy room, a cosy flat), Gemütlichkeit connotes, much more than cosiness, the notion of belonging, social acceptance, cheerfulness, the absence of anything hectic and the spending of quality time in a place as described above.
"Abandon all burden, ye who enter here."
The underlying concept is that social tensions and certain environments can cause stress, resulting in a feeling of alienation. Gemütlichkeit is an active way of preventing such negative influences by going to places and/or meeting with people that are regarded to be gemütlich. A gemütlich person again is one that takes part in this lifestyle and knows about the tensions he/she is able to cause, and thus tries to avoid these things actively. This way an agreement is established to make an "environmentally cosy" site (Heuriger, garden, cellar, backyard restaurant, living room...) "socially cosy". One characteristic of a gemütlich situation is that one could blind out everything else (past, future, other places and absent people) and yet everything would be fine (an eternal "now and here"). Germans describe that as "leaving everything at the doorstep" (though a gemütlich place doesn't necessarily have to be inside a house).
A similar word exists in Dutch as well, gezelligheid. There is also a Danish equivalent (hygge), which basically means the same. In Russian, the word commonly translated as cosiness, уют (ujut), carries almost identical connotations as the German word.
Queen Victoria is said to have been one of the first to use the adjective gemütlich in English. Today, the word is frequently used in descriptions of holiday destinations. Gemütlichkeit may be sought by adults as well as young people, who do not necessarily always prefer excitement.