the word is a modern compound, created in the late 20th century to describe the new hybrid sport. it directly combines 'wind', the natural force that fills the sail, with 'surfing', the activity of riding ocean waves on a board. the addition of the '-ing' suffix nominalizes the action, turning it into the name of the sport itself. the term's logic is transparently descriptive, literally meaning "the activity of surfing powered by the wind."

Structure: wind + surf + ing wind (old english, meaning 'air in motion', the natural element that propels the craft); surf (american english, from 'surf' meaning the swell of the sea, here referring to the activity of riding on waves); ing (old english, suffix forming verbal nouns indicating an action or activity).