sturdy adj.

c. 1300 (late 12c. as a surname), sturdi, "hard to manage, reckless, violent; fierce, cruel; bold, strong in fighting; stern, severe; ill-humored; disobedient, rebellious," from Old French estordi (11c., Modern French étourdi) "violent," originally "dazed," past participle of estordir, estordiir "to daze, stun, stupefy," from Vulgar Latin *exturdire (source also of Spanish atordir "to stun, daze," earlier estordir), which some presume to be from Latin intensive prefix ex- (see ex-) + turdus "thrush" (see thrush (n.1)).

The usual suggestion for that proposed origin is that the image is of thrushes eating grape remnants at wineries and then acting drunk. Klein notes that Italian tordo "thrush" also means "simpleton," and French has the expression soûl comme une grive "drunk as a thrush." OED, however, regards all this as "open to grave objection." Century Dictionary compares Latin torpidus "dull" (Lewis & Short has an *ex-torpesco).

In reference to a person, the sense of "solidly built, strong and hardy" is from late 14c. Related: Sturdily; sturdiness. Sturdy-boots "obstinate person" is from 1762; a sturdy beggar in old language was one capable of work (c. 1400).