1. Action; process; practice: terrorism.
2. Characteristic behavior or quality: heroism.
a. State; condition; quality: pauperism.
b. State or condition resulting from an excess of something specified: strychninism.
4. Distinctive or characteristic trait: Latinism.
a. Doctrine; theory; system of principles: pacifism.
b. An attitude of prejudice against a given group: racism.
[Middle English -isme, from Old French, from Latin -ismus, from Greek -ismos, n. suff.]
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.