myelin

What it means

1. countableuncountableanatomyA white, fatty material, composed of lipids and lipoproteins, that surrounds the axons of nerves.

   This gene controls the production of an insulating sleeve that wraps around neurons. Known as myelin, it is crucial for long-range communication in the brain.

   2018 December 13, Carl Zimmer, “Narrower Skulls, Oblong Brains: How Neanderthal DNA Still Shapes Us”, in The New York Times, →ISSN

   1 more example

   As the result of prolonged action of water upon myelin, bird's-nests-cells are also said to be produced, and we are certain we have seen, as the result of such prolonged action of water, the appearances thus compared.

   1868 January, Edmund Montgomery, “On the Formation of so-called Cells in Animal Bodies”, in The American Journal of the Medical Sciences, page 203

In a sentence

As the result of prolonged action of water upon myelin, bird's-nests-cells are also said to be produced, and we are certain we have seen, as the result of such prolonged action of water, the appearances thus compared.

1868 January, Edmund Montgomery, “On the Formation of so-called Cells in Animal Bodies”, in The American Journal of the Medical Sciences, page 203

Where it comes from

1. Ancient Greekμυελός (muelós)
2. Englishmyelo-
3. Englishmyelin

From myelo- + -in. From Ancient Greek μυελός (muelós, “marrow”).