To save this word, you'll need to log in.
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
Comments on primitive segment
What made you want to look up primitive segment? Please tell us where you read or heard it (including the quote, if possible).
Test Your Vocabulary
Intact Latin Quiz
- What did focus mean in Latin?
Can you spell these 10 commonly misspelled words?
TAKE THE QUIZ
Test Your Knowledge - and learn some interesting things along the way.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
- Intact Latin Quiz
What did each of these words mean to ancient Romans?
Take the quiz - The Eponym Quiz
Do you know these words that come from names?
Take the quiz - Spell It
Can you spell these 10 commonly misspelled words?
Take the quiz - Dictionary Devil
The dictionary has been scrambled—can you put it back together?
Play the game
Share primitive segment