1. The act of splitting or cleaving.
2. The state of being split or cleft; a fissure or division.
3. Mineralogy The splitting or tendency to split of a crystallized substance along definite crystalline planes, yielding smooth surfaces.
a. The series of mitotic cell divisions that produces a blastula from a fertilized ovum. It is the basis of the multicellularity of complex organisms. Also called segmentation.
b. Any single cell division in such a series.
5. Chemistry The splitting of a complex molecule, such as a polysaccharide, into simpler molecules.
6. Informal The cleft between a woman's breasts as revealed by a low-cut garment.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2017 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.
American Heritage Dictionary Products
The American Heritage Dictionary, 5th Edition
The American Heritage Dictionary of Idioms
The American Heritage Roget's Thesaurus
Curious George's Dictionary
The American Heritage Children's Dictionary
The American Heritage Dictionary of Indo-European Roots
The American Heritage Student Grammar Dictionary
The American Heritage Desk Dictionary + Thesaurus
The American Heritage Science Dictionary
The American Heritage Dictionary of Business Terms
The American Heritage Student Dictionary
The American Heritage Essential Student Thesaurus