Any of various fishes lacking jaws and true teeth and having a circular sucking mouth, including the hagfishes and the lampreys.
[From New Latin Cyclostomī and Cyclostomata, class names : CYCLO- + Greek stoma, stomat-, mouth.]
cy·closto·mate′ (sī-klŏstə-māt′, -mĭt) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.