alternative

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The choice between two mutually exclusive possibilities.
2. n. A situation presenting such a choice.
3. n. Either of these possibilities. See Synonyms at choice.
4. n. Usage Problem One of a number of things from which one must be chosen.
5. adj. Allowing or necessitating a choice between two or more things.
6. adj. Existing outside traditional or established institutions or systems: an alternative lifestyle.
7. adj. Espousing or reflecting values that are different from those of the establishment or mainstream: an alternative newspaper; alternative greeting cards.
8. adj. Usage Problem Substitute or different; other.

Century Dictionary and Cyclopedia

1. Of two things, such that only one can be selected or only one is possible, etc.; mutually exclusive.
2. Affording a choice between two things, or a possibility of one thing out of two; given or offered for selection, as against something else: as, an alternative proposition; he presented an alternative statement.
3. Alternate; reciprocal. Holland.
4. In botany, having the parts of the inner whorl alternate with the outer: applied to the estivation or arrangement of the parts of the perianth in the bud.
5. n. A choice between two things; a possibility of one of two things.
6. n. One of two things of which either is possible or may be chosen. In strictness the word cannot be applied to more than two things; when one thing only is possible, there is said to be no alternative.
7. n. In the Roman Catholic Church, an arrangement by which the pope nominates to vacant benefices only in alternate months, at other times leaving the nomination to the bishop of the diocese or to the regular patron. The month counted is that in which the benefice becomes vacant.

Wiktionary

1. adj. Relating to a choice between two or more possibilities
2. adj. Not traditional, outside the mainstream, underground (e.g., alternative medicine, alternative lifestyle, alternative rock).
3. adj. this sense?) Other.

GNU Webster's 1913

1. adj. Offering a choice of two things.
2. adj. Disjunctive.
3. adj. obsolete Alternate; reciprocal.
4. 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.
5. 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.
6. n. The course of action or the thing offered in place of another.
7. n. A choice between more than two things; one of several things offered to choose among.

WordNet 3.0

1. adj. serving or used in place of another
2. adj. pertaining to unconventional choices
3. adj. necessitating a choice between mutually exclusive possibilities
4. n. one of a number of things from which only one can be chosen