Merriam-Webster Logo
SINCE 1828
Menu
dictionary thesaurus

primitive segment

noun

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

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Learn More about primitive segment

Statistics for primitive segment

Look-up Popularity

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).

Show Comments  Hide Comments 

WORD OF THE DAY

insuperable

Listen to the pronounciation of insuperable

incapable of being surmounted or overcome

Get Word of the Day daily email!

Test Your Vocabulary

Finance Words Quiz

  • a-piggy-bank
  • The etymology of mortgage is related most closely to which two words?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words at Play
Ask the Editors
Word Games