||As*trag"a*lus (&?;), n. [L. See
Astragal.] 1. (Anat.) The ankle bone, or
hock bone; the bone of the tarsus which articulates with the tibia at the
ankle.
2. (Bot.) A genus of papilionaceous plants,
of the tribe Galegeæ, containing numerous species, two of
which are called, in English, milk vetch and licorice vetch.
Gum tragacanth is obtained from different oriental species,
particularly the A. gummifer and A. verus.
3. (Arch.) See Astragal, 1.