Coordinate terms: single, double (aviation) A two- engine aircraft. (crystallography) A twin crystal. (US) A twin size mattress; or a bed designed for such a mattress. (African-American Vernacular, slang) A friendly term of address, typically for men.
CNET: Twin-Size Mattress Dimensions: What You Need to Know Before You Buy
Mattress sizes range from Twin for children to California King for tall adults and couples. Factors like room size, budget and whether you sleep alone or with a partner should guide your choice.
One twin, the 'donor' twin, is small and anemic, the other, the 'recipient' twin, is large and polycythemic. The lives of both twins are endangered by this condition.
There are different types of twins, identical and fraternal being the most common. Identical, or monozygotic, twins develop from the same fertilized egg that splits into two. These twins are...
If you have a twin brother or sister, the two of you are always the same age. There are identical twins, who have the same DNA, and fraternal twins, who are more like two siblings who happen to be born at the same time.
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.
Fraternal twins happen when two different eggs are fertilized by two different sperm (typically, from the same donor) in the same ovulation cycle. They come from two separate zygotes, so they each have different genes. Identical twins are the result of one zygote that splits in two.