from The Century Dictionary and Cyclopedia
- Not chary; not frugal; not careful; heedless.
Sorry, no etymologies found.
Perhaps it was human and correctly natural that Knight never once thought whether he did not owe her a little sacrifice for her unchary devotion in saving his life.
Otherwise, I agree with you that a people unchary of its honor at any sacrifice is fit only to be enslaved by some nobler race.