Origin and history of spavin

small brown and gray bird (Passer domesticus), of European origin but widely spread by colonists and now naturalized in North America, Australia, etc.; Middle English sparwe, from Old English spearwa, from Proto-Germanic *sparwan (source also of Old Norse spörr, Old High German sparo, German Sperling, Gothic sparwa).

This is reconstructed to be from PIE *spor-wo-, from a root *sper- (3), forming names of small birds in Germanic, Baltic, and Greek (source also of Old Prussian spurglis "sparrow;" Greek sparasion "small, sparrow-like bird," a diminutive form; spergoulos "small field bird," psar "starling").

The sparrow is a conirostral granivorous bird, whose food is principally seeds and grain, yet it has been introduced in many countries for the purpose of destroying noxious insects. ... It speedily becomes a pest wherever introduced, and seldom destroys noxious insects to any appreciable extent. It was brought into the United States from Germany about 1869, and is now probably more numerous than any single native bird. [Century Dictionary, 1895]

In English use, with qualifying words, in reference to many small, sparrow-like birds (e.g. snow-sparrow for "junco"). Used also of small, active, quick-witted persons, especially London cockneys (by 1861). Sparrow-pie (1881) was the proverbial dish of those who gained sharper wits. Of things, indicating those of a small or inferior sort.

Sparrowfarts (1886) was Cheshire slang for "very early morning." To be sparrow-blasted (1650s) was to be balefully stricken (sparrow-blasting is from 1580s), but the sense is unclear.