An ion or group of ions having a positive charge and characteristically moving toward the negative electrode in electrolysis.
[Greek kation, something going down, from neuter present participle of katienai, to go down : kat-, kata-, cata- + ienai, to go; see ei- in the Appendix of Indo-European roots.]
cat′i·onic (kăt′ī-ŏnĭk) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.