The Book of Human Emotions: From Ambiguphobia to Umpty - 154 Words from Around the World for How We Feel - Tiffany Watt Smith 2016
Literally the word for a boat sail, hwyl is a wonderfully onomatopoeic Welsh word (pronounced who-eel) that means exuberance or excitement, as if clipping along on a gust of wind. Used to describe flashes of inspiration, a singer’s gusto or raised spirits at parties, hwyl is also the word for goodbye:
Hwyl fawr—Go with the wind in your sails.
See also: JOY.