Belonging to the same taxonomic genus; congeneric
Having the same (kind of) origin or action
To split, part; to go away, depart.
To separate, divide.
To join, unite; to form links between (now especially of two places in different countries); to pair with.
To be, or be like, a pair of twins (for example, to dress identically); to be paired or suited.
To give birth to twins.
To be, or be like, a twin to (someone else); to match in some way.
A twin size mattress or a bed designed for such a mattress.
A room in a hotel, guesthouse, etc. with two beds; a twin room.
A twin crystal.
Either of two similar or closely related objects, entities etc.
A two-engine aircraft.
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.
Forming a pair of twins.
Double; dual; occurring as a matching pair.