n. pl. cri·te·ri·a (-tîrē-ə) or cri·te·ri·ons
A standard, rule, or test on which a judgment or decision can be based.
[Greek kritērion, from kritēs, judge, from krīnein, to separate, judge; see krei- in the Appendix of Indo-European roots.]
cri·teri·al (-əl) adj.
Usage Note: Like phenomenon, criterion comes directly from Greek and is singular. In standard usage, the plural is generally criteria, although criterions is sometimes used as well. Properly speaking, the form criteria should never be a singular noun, and phrases like this criteria and single criteria are widely viewed as erroneous. Similarly, the plural criterias is also viewed as a mistake and is usually edited out of published prose.
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.