Synonyms for Medulla (same or very similar meaning)
WordNet sense 1 (a white fatty substance that forms a medullary sheath around the axis cylinder of some nerve fibers):
myelin, myeline
WordNet sense 2 (lower or hindmost part of the brain; continuous with spinal cord; (`bulb' is an old term for medulla oblongata)):
bulb, medulla oblongata
From the ODE community, based on WordNet
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