What's Trending Now
More Trending Words
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
From the M-W Editors
There's more!
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!
Seen and Heard
What made you want to look up primitive segment? Please tell us where you read or heard it (including the quote, if possible).
Writing? Check your grammar now!