sclerotome

noun

1. Embryology. the part of a mesodermal somite contributing to the development of the vertebrae and ribs.
2. Surgery. an instrument for use in performing a sclerotomy.
3. Zoology. a fibrous partition separating successive myotomes.

n.

1. A knife used in sclerotomy.
2. A group of mesenchymal cells emerging from the ventromedial part of a mesodermic somite and migrating toward the notochord.