Having two parts.
Having two participants; joint.
Having vertices that can be divided into two independent sets (see bigraph)
Divided into two at the base.
Second.
See other (determiner) below.
Alien.
Different.
An other, another (person, etc), more often rendered as another.
The other one; the second of two.
To regard, label, or treat as an "other", as not part of the same group; to view as different and alien.
To treat as different or separate; segregate; ostracise.
Not the one or ones previously referred to.