• WordNet 3.6
    • adj medullated (of neurons) covered with a layer of myelin
    • ***
Webster's Revised Unabridged Dictionary
    • a Medullated (Anat) Furnished with a medulla or marrow, or with a medullary sheath; as, a medullated nerve fiber.
    • ***
Century Dictionary and Cyclopedia
    • medullated Having a medulla.
    • ***
Chambers's Twentieth Century Dictionary
    • Medullated provided with a medullary sheath
    • ***


Chambers's Twentieth Century Dictionary
L. medulla, marrow.


In literature:

The nerve fibres of this system, like the nerve fibres of invertebrates, are non-medullated.
"Text Book of Biology, Part 1: Vertebrata" by H. G. Wells
They give off a number of short dendrites with claw-like endings, and a fine non-medullated neuraxon process.
"Encyclopaedia Britannica, 11th Edition, Volume 4, Slice 4" by Various