[ ō′vər-dŏm′ə-nəns ]
The condition in which a heterozygote has a phenotype that is more pronounced or better adapted than that of either homozygote.
Related formso′ver•dom′i•nant adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Examples from the Web for overdominance
According to statistical studies, overdominance by parents decreases the chance of successful marriage.