- one of a pair of twins, not necessarily resembling each other, or of the same sex, that develop from two separately fertilized ova.
Compare identical twin.
Origin of fraternal twin
First recorded in 1900–05
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- Twins that derive from separately fertilized ova and that have different genetic makeup. They may be of the same or opposite sex.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.