The Collaborative International Dictionary of English v.0.48:
Sturdy \Stur"dy\, a. [Compar. Sturdier; superl. Sturdiest.]
[OE. sturdi inconsiderable, OF. estourdi stunned, giddy,
thoughtless, rash, F. ['e]tourdi, p. p. of OF. estourdir to
stun, to render giddy, to amaze, F. ['e]tourdir; of uncertain
origin. The sense has probably been influenced by E. stout.]
1. Foolishly obstinate or resolute; stubborn; unrelenting;
This sturdy marquis gan his hearte dress
To rue upon her wifely steadfastness. --Chaucer.
This must be done, and I would fain see
Mortal so sturdy as to gainsay. --Hudibras.
A sturdy, hardened sinner shall advance to the
utmost pitch of impiety with less reluctance than he
took the first steps. --Atterbury.
2. Resolute, in a good sense; or firm, unyielding quality;
as, a man of sturdy piety or patriotism.
3. Characterized by physical strength or force; strong;
lusty; violent; as, a sturdy lout.
How bowed the woods beneath their sturdy stroke!
4. Stiff; stout; strong; as, a sturdy oak. --Milton.
He was not of any delicate contexture; his limbs
rather sturdy than dainty. --Sir H.
Syn: Hardy; stout; strong; firm; robust; stiff.