noun.
In anatomy: The forearm or antebrachium; the arm from the elbow to the wrist.
noun.
The inner bone of the forearm; the ulna.
noun.
A linear unit derived from the length of the forearm.
noun.
In entomology, one of the veins, nerves, or ribs of an insect's wing; a cubital rib, succeeding the radius or sector. See phrases under cubitus.