Family Group
twin Audio
twin [ twin ]
Subclass of:
Multiple Birth Offspring
Definitions related to twin sibling (person):
  • (twin) Either of two offspring born from the same pregnancy.
    NCI
    U.S. National Cancer Institute, 2021
  • (twin) The scoper and player were carried in the same womb and shared common biological parents.
    NCI Health Level 7 Vocabulary
    U.S. National Cancer Institute, 2018
  • (twins) Two individuals derived from two FETUSES that were fertilized at or about the same time, developed in the UTERUS simultaneously, and born to the same mother. Twins are either monozygotic (TWINS, MONOZYGOTIC) or dizygotic (TWINS, DIZYGOTIC).
    NLM Medical Subject Headings
    U.S. National Library of Medicine, 2025
  • Twin, either of two young who are simultaneously born from one mother. Twinning, common in many animals, is of two biological kinds: the one-egg (monozygotic), or identical, type and the two-egg (dizygotic), or fraternal, type. The latter type is more usual and can be thought of simply as a litter...
    Encyclopedia Britannica
    Encyclopedia Britannica, Inc., 2025
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