What is the meaning of Twin?

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.

Either of two similar or closely related objects, entities etc.

A room in a hotel, guesthouse, etc. with two beds; a twin room.

A twin size mattress or a bed designed for such a mattress.

A two-engine aircraft.

A twin crystal.

To separate, divide.

To split, part; to go away, depart.

To join, unite; to form links between (now especially of two places in different countries); to pair with.

To give birth to twins.

To be, or be like, a twin to (someone else); to match in some way.

To be, or be like, a pair of twins (for example, to dress identically); to be paired or suited.

Double; dual; occurring as a matching pair.

Forming a pair of twins.

Alternative form of twyn

Alternative form of twinn

Source: wiktionary.org