(n.) An offer of two things, one of which may be chosen, but not both; a choice between two things, so that if one is taken, the other must be left.
(n.) Either of two things or propositions offered to one's choice. Thus when two things offer a choice of one only, the two things are called alternatives.
(n.) The course of action or the thing offered in place of another.
(n.) A choice between more than two things; one of several things offered to choose among.