Not equal.
Different.
See other (determiner) below.
Alien.
Second.
Not the one or ones previously referred to.
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.