medulla noun. [mɛ'dʌlǝ] LME.
[Latin = pith, marrow, perh. from medius MID adjective.]
Biology.
1. Anatomy.
a. The (inner) substance of the brain and spinal cord. Now rare or obsolete. LME.
b. Anatomy & Zoology. The marrow of a bone. Also, the central part or substance of various organs or structures where distinguishable from a cortex, e.g. of a kidney, adrenal gland, hair, or feather; pith. LME.
ADRENAL medulla.
c. In full medulla oblongata [ɒblɒŋ'gɑ:tǝ] [Latin, lit. 'prolonged marrow']. The continuation of the spinal cord within the cranium, forming the hindmost part of the brain and containing regulatory centres for the heart, lungs, swallowing reflex, etc. L17.
d. The myelin sheath of a nerve. Now rare. M19.

2. Botany. The pith or soft internal tissue of a plant. M17.

3. fig. The essential or central matter of a subject. Also, a compendium, a summary. M17-M18.

[TahlilGaran] English Dictionary ▲