antidote

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A remedy or other agent used to neutralize or counteract the effects of a poison.
2. n. An agent that relieves or counteracts: jogging as an antidote to nervous tension.
3. v. To relieve or counteract with an antidote: "Hallie's family life is laced with the poison of self-hatred, a poison that Sam has antidoted with love and understanding" ( Christopher Swan).

Century Dictionary and Cyclopedia

1. n. A medicine adapted to counteract the effects of poison or an attack of disease.
2. n. Whatever prevents or tends to prevent or counteract injurious influences or effects, whether physical or mental; a counteracting power or influence of any kind.
3. n. Synonyms Remedy, cure, counteractive, corrective.
4. To furnish with preservatives; preserve by antidotes; serve as an antidote to; counteract.

Wiktionary

1. n. A remedy to counteract the effects of poison (often followed by "against," "for," or "to").
2. n. Something that counteracts or prevents something harmful.
3. v. transitive To counteract as an antidote.

GNU Webster's 1913

1. n. A remedy to counteract the effects of poison, or of anything noxious taken into the stomach; -- used with against, for, or to.
2. n. Whatever tends to prevent mischievous effects, or to counteract evil which something else might produce.
3. v. To counteract or prevent the effects of, by giving or taking an antidote.
4. v. To fortify or preserve by an antidote.

WordNet 3.0

1. n. a remedy that stops or controls the effects of a poison