Definition of "heterosis" [‖Het•e•ro•sis]

• See hybrid vigor. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "It has a phenomenon associated with it called 'heterosis' - otherwise known as 'hybrid vigor.'"
• "Hybrid vigor, also known as heterosis, is the miraculous phenomenon by which intercrossing two varieties of plants produces more vigorous hybrid offspring with higher yields."
• "Intercrossing different varieties of plants frequently produces hybrid offspring with superior vigor and increased yields, in a poorly understood phenomenon known as heterosis"