A wind pernicious to flowers and health. In Italy one of the South winds was so called; its modern name is the Siroco. (Greek, austeros, hot, dry). In England it is a damp wind, generally bringing wet weather.
Nought but putrid streams and noisome fogs. For ever hung on drizzly Auster's beard.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894