cannon bone
noun
,
Zoology
1.
the greatly developed middle metacarpal or metatarsal bone of hoofed quadruped mammals, extending from the hock to the fetlock.
Origin
1825-35;
cannon
in obsolete sense “tube”
British Dictionary definitions for
cannon bone
cannon bone
noun
1.
a bone in the legs of horses and other hoofed animals consisting of greatly elongated fused metatarsals or metacarpals