from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. The bone extending from the elbow to the wrist on the side opposite to the thumb in humans.
  • n. A corresponding bone in the forelimb of other vertebrates.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. The bone of the forearm that extends from the elbow to the wrist on the side opposite to the thumb, corresponding to the fibula of the hind limb. Also, the corresponding bone in the forelimb of any vertebrate.

from the GNU version of the Collaborative International Dictionary of English

  • n. The postaxial bone of the forearm, or brachium, corresponding to the fibula of the hind limb. See radius.
  • n. An ell; also, a yard.

from The Century Dictionary and Cyclopedia

  • n. The inner one of the two bones of the forearm, between the elbow and the wrist, the other being the radius; the bone which makes a strict hinge-joint at the elbow with the humerus, and about which the radius revolves in pronation and supination, when the ulna reaches to the wrist and these movements are practicable.
  • n. In entomology, the stigmatic or marginal vein of the fore wing.
  • n. A unit of length; a cubit; an ell.
  • n. In ichthyology, the hypereoracoid.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. the inner and longer of the two bones of the human forearm


Latin, elbow, forearm.
(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin ulna ("elbow"). (Wiktionary)


  • Plaque-clogged arteries in the abdomen suggest a red-meat eater; black-encrusted lungs signify long-term nicotine addiction; the faint indentation in the ulna is the scarred evidence of an arm broken in childhood.

    Body of Knowledge

  • For four or five days I thought over the history of his injury and the resulting inability to rotate the radius around the ulna -- in other words, to turn his hand over.

    With Sabre and Scalpel. The Autobiography of a Soldier and Surgeon

  • At the elbow, which is the first angle of the wing, reaching backward when the wing is folded, the humerus articulates in a wisely designed way with two other bones, called the ulna and radius, which together constitute the forearm and extend to the wrist joint.

    Our Bird Comrades

  • (The ulna is the bone that reaches the wrist on the pinkie side.)

    Scientific American

  • The medial and lateral heads originate on the upper-arm bone and attach on the ulna, which is one of the forearm bones.


  • In the Negro, the 'ulna', the longest bone of the fore-arm, is nearly of the same length as the 'os humeri', the latter being from one to two inches longer.

    The Bushman — Life in a New Country

  • "The fracture of the ulna is a simple one," said the spokesman, "and will become all right in the ordinary course of nature.

    The Albert Gate Mystery Being Further Adventures of Reginald Brett, Barrister Detective

  • A left humerus of which the upper-third is wanting, and which is so much slenderer than the right as apparently to belong to a distinct individual; a left 'ulna', which, though complete, is pathologically deformed, the coronoid process being so much enlarged by bony growth, that flexure of the elbow beyond a right angle must have been impossible; the anterior fossa of the humerus for the reception of the coronoid process being also filled up with a similar bony growth.

    Lectures and Essays

  • Moving his right arm above water Alex let out a terrified shriek, his ulna and radius were protruding through his skin, and his arm was dangling as he desperatly tried to keep from drowning.

    Superhero Nation: how to write superhero novels and comic books » Black Cat’s Review Forum

  • Then, almost immediately, Spooky found the ulna of a very large bird (the bone measures 22 cm. along the mid-line).

    "Back to work," growled the platypus, and the dodo, she agreed.


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  • Part of the Century Dictionary definition says this: "In man, in animals generally which use their fore paws as hands, and in birds it is perfect, and extends the whole length of the forearm."

    April 19, 2011