1. Biology The existence among animals of the same species of two distinct forms that differ in one or more characteristics, such as coloration, size, or shape.
2. Botany The occurrence of two distinct forms of the same parts in one plant, as in the juvenile and adult leaves of ivy.
3. Chemistry & Physics Dimorphic crystallization.
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.