Gust entered English in the late sixteenth century from Old Norse gustr (a cold blast of wind), from Proto-Germanic *gustiz. Despite the strong Norse influence on English vocabulary during the Danelaw period (9th-11th centuries), gust is a relatively late borrowing — it appears in English texts only from the 1580s onward, suggesting it may have survived in Northern English or Scottish dialect before entering the standard language, or been re-borrowed from Scandinavian contact in later centuries.
The word's phonetic quality seems to embody its meaning. The short, sharp vowel and abrupt final consonant of gust mimic the sudden, brief quality of the phenomenon it describes. Unlike breeze (soft and extended), wind (broad and sustained), or gale (sweeping and powerful), gust is compact and percussive — a single syllable for a single burst. Whether this sound-meaning correspondence is genuine onomatopoeia or coincidental, it contributes to the word's expressiveness.
In meteorology, a gust has a precise technical definition: a sudden increase in wind speed above the sustained average, lasting less than twenty seconds. Gusts are caused by turbulent eddies in the atmosphere, typically generated by surface friction, thermal convection, or the passage of weather fronts. The ratio of peak gust speed to sustained wind speed (the gust factor) is a critical parameter in structural engineering — buildings, bridges, and other structures must be designed to withstand not just average wind loads but the peak forces delivered by gusts.
The metaphorical extension of gust to non-wind phenomena — a gust of rain, a gust of laughter, a gust of emotion — capitalizes on the word's connotation of sudden, brief intensity. These metaphors share a common structure: something normally moderate or steady suddenly surges in force, then subsides. A gust of anger is not sustained rage but a flash of temper; a gust of enthusiasm is not steady commitment but a sudden flare of interest. The meteorological pattern — burst, peak, subsidence — maps perfectly onto emotional and experiential phenomena.
There is an entirely separate English word gust, now obsolete, meaning taste or relish, from Latin gustus (taste). This Latin gust gave English gusto (enthusiastic enjoyment), disgust (loss of taste, revulsion), and degustation (a tasting, especially of wine). The two gusts — the Norse wind and the Latin taste — are unrelated false friends that happened to converge in English spelling, creating a homograph that can confuse readers of historical texts where both senses were current.