ulna

/ˈʌlnə/

/ˈʌlnə/

Other forms: ulnas; ulnae

Your ulna is a bone in your arm — it sits in the forearm beside the radius bone, connecting your pinky finger to your elbow.

The ulna is longer than the radius, and you need it for things like turning a car's steering wheel and throwing a ball. Because the ulna extends to the very tip of the elbow, it's sometimes called the "elbow bone," and in fact ulna means "elbow" in Latin. Most animals have an ulna, although it's often at least partially fused to the radius.

Definitions of ulna

1. noun

   the inner and longer of the two bones of the human forearm
   synonyms: elbow bone

   type of:

   arm bone

   a bone in the arm