1. The protective cap or hood covering the spore case of a moss or related plant.
2. A similar hoodlike or caplike structure, such as a root cap.
[Medieval Latin, from Greek kaluptra, veil, from kaluptein, to cover; see kel-1 in the Appendix of Indo-European roots.]
ca·lyptrate′ (-trāt′) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.