One of a group of things of the same kind.
An additional one of the same kind.
One that is different from the current one.
Not the same; different.
One more/further, in addition to a former number; a second or additional one, similar in likeness or in effect.
Any or some; any different person, indefinitely; anyone else; someone else.
Other; in addition to previously mentioned items.
Otherwise, if not.
For otherwise; or else.