Definition of prismatic layer
1 or less commonly prismatic tissue : a layer of secondary tissue developed internally by the cambium of some lycopods (as the quillworts) and interpreted as xylem, phloem, or both
2 : the middle layer of the shell of a mollusk consisting essentially of calcium carbonate arranged in prisms
Test Your Vocabulary
Slippery Words Quiz—Changing with the Times
- What is an earlier meaning of nice?

Test your visual vocabulary with our 10-question challenge!
TAKE THE QUIZ
Spell words. Make bears.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
Share prismatic layer