Definition of primitive segment
: any one of the transverse segments into which the body of the embryo of vertebrates becomes marked off by the formation beginning first in the neck region of a series of distinctly limited masses of mesoblast cells on each side of the neural tube
— called also protovertebra
incapable of being surmounted or overcome
Get Word of the Day daily email!
Love words? Need even more definitions?Merriam-Webster unabridged
Words at Play
Ask the Editors
- On Contractions of Multiple Words
- A Look at Uncommon Onomatopoeia
- Is Singular 'They' a Better Choice?