either of two offspring born at the same time from the same pregnancy
"My twin was crying because she had a fever while I was perfectly healthy."
a waterfall in the Snake River in southern Idaho
"Visitors often take photos at Twin Falls to capture the powerful cascade of the Snake River."
a duplicate copy
"The software updated automatically, creating an exact twin of my working files on the backup drive."
Either of two people (or, less commonly, animals) who shared the same uterus at the same time; one who was born at the same birth as a sibling.
"After years of waiting, fans finally cheered when a new twin joined the team lineup."
A player who plays for the Minnesota Twins.
In plain English: A twin is one of two people who are born at the same time and share the same parents.
"The twins were born on the same day and look exactly alike."
To separate, divide.
"The twin of a single cell creates two distinct organisms through division."
In plain English: To twin means to make two things look exactly the same by matching their style or design.
"The printer failed because both sides of the page were printed as twins."
double; dual; occurring as a matching pair
"The factory installed twin engines to ensure that if one fails, the other can keep the vehicle moving safely."
In plain English: When something is twin, it means there are two of them that are exactly alike and come from the same source.
"My twin sister and I look exactly alike."
Usage: Use this adjective to describe two people or things that are born at the same time and share identical genetic material, rather than simply being similar in appearance. It is often confused with terms like "identical" when referring specifically to biological siblings who develop from one fertilized egg.
The word "twin" comes from the Old English words for two or double. It traveled into modern English through Middle English, retaining its original meaning of referring to a pair born at the same time.