Distinguishing by contrast
Having the quality of contradistinction
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.