A negatively charged ion, especially the ion that migrates to an anode in electrolysis.
[From Greek, neuter present participle of anienai, to go up : ana-, ana- + ienai, to go; see ei- in the Appendix of Indo-European roots.]
an′i·onic (-ŏnĭk) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.