Definitions
1.NounEither 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.
2.NounEither of two similar or closely related objects, entities etc.
3.NounA room in a hotel, guesthouse, etc. with two beds; a twin room.
4.NounA two-engine aircraft.
5.NounA twin crystal.
6.NounA twin size mattress; or a bed designed for such a mattress.
7.NounA friendly term of address, typically for men.
8.VerbTo separate, divide.
9.VerbTo split, part; to go away, depart.
10.VerbTo join, unite; to form links between (now especially of two places in different countries); to pair with."Reading, the English town, is twinned with Clonmel in Ireland.; Coventry twinned with Dresden as an act of peace and reconciliation, both cities having been heavily bombed during the war."
11.VerbTo give birth to twins.
12.VerbTo be, or be like, a twin to (someone else); to match in some way.
13.VerbTo be, or be like, a pair of twins (for example, to dress identically); to be paired or suited.
14.AdjectiveDouble; dual; occurring as a matching pair."twin beds, twin socks"
15.AdjectiveForming a pair of twins."the twin boys"