Today's Word of the Day means...
One of two offspring born at the same birth. adj.
Being two or one of two offspring born at the same birth.
Consisting of two identical or similar parts; double.
twinning twin·ning (twĭn'ĭng)
The bearing of twins.
A pairing or union of two similar or identical objects.
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 of two. In humans, psychological studies of sets of identical twins, since they are genetically identical, have provided much otherwise unobtainable information on the relative effects of genetic endowment and environment. See also multiple birth.