Kéfi
Etymology
From Greek (κέφι), borrowed via Turkish “keyif” from Arabic “kayf” (state, mood, well-being). In Greek it took on the meaning of exuberant good spirits and festive abandon, the energy said to be essential to a real celebration. It is the same root that gives Turkish keyif, though the Greek sense leans more toward exuberance than repose.
noun · /KEH-fee/
The high spirits, joy, and passion that make you want to let loose and celebrate.
What it names
The uninhibited, contagious surge of mood that gets people up to dance, sing, or throw themselves fully into a good time.
Example
By midnight the whole taverna had kéfi, and even the shy accountant was dancing on his chair.
Related idea
Spanish duende is a dark, soulful artistic power; kéfi is brighter and more communal — the joyful high spirits of a shared celebration rather than a haunting authenticity.