against

American Heritage® Dictionary of the English Language, Fourth Edition

1. prep. In a direction or course opposite to: row against the current.
2. prep. So as to come into forcible contact with: waves dashing against the shore.
3. prep. In contact with so as to rest or press on: leaned against the tree.
4. prep. In hostile opposition or resistance to: struggle against fate.
5. prep. Contrary to; opposed to: against my better judgment.
6. prep. In competition with: race against the record holder.
7. prep. In contrast or comparison with the setting or background of: dark colors against a fair skin.
8. prep. In preparation for; in anticipation of: food stored against winter.
9. prep. As a defense or safeguard from: protection against the cold.
10. prep. To the account or debt of: drew a check against my bank balance.
11. prep. Directly opposite to; facing.

Century Dictionary and Cyclopedia

1. Of motion or direction: In an opposite direction to, so as to meet; toward.
2. upon: as, to strike against a rock; the rain beats against the window: to ride against the wind.
3. Of position: In an opposite position; directly opposite; in front of: in this sense often preceded by over: as, a ship is against the mouth of a river.
4. In contact with; bearing upon: as, to lean against a wall; in optical contact with (something behind); athwart: as, the ship loomed up dark and grim against the sky.
5. Of action or purpose: In opposition to; in contrariety to; adverse or hostile to: as, twenty votes against ten; against law, reason, or public opinion.
6. In resistance to or defense from: as, protection against burglars, cold, fire, etc.; to warn one against danger; the public are cautioned against pickpockets.
7. In provision for; in preparation for; in anticipation of; with reference to.
8. In exchange for; in return for; as a balance to: as, an exporter draws against merchandise shipped.
9. For the purpose of consuming time: as, he talked against time, that is, merely to gain time, a method sometimes adopted by members of legislative and deliberative assemblies who desire to defeat some measure or motion by lapse of time, or to gain time for supporters to assemble.
10. (by ellipsis). Against the time that; by the time that; before: as, be ready against I get back.

Wiktionary

1. prep. In a contrary direction to.
2. prep. Close to.
3. prep. In front of; before a background.
4. prep. In physical contact with.
5. prep. In physical opposition to, or in collision with.
6. prep. In contrast and/or comparison with.
7. prep. In competition with, versus.
8. prep. In opposition to.
9. prep. In exchange for.
10. prep. As counterbalance to.
11. prep. As a charge on.
12. prep. As protection from.
13. prep. obsolete Exposed to.
14. prep. In anticipation of; in preparation for (a particular time, event etc.).
15. conj. obsolete By the time that (something happened); before.

GNU Webster's 1913

1. prep. Abreast; opposite to; facing; towards; ; -- in this sense often preceded by over.
2. prep. From an opposite direction so as to strike or come in contact with; in contact with; upon.
3. prep. In opposition to, whether the opposition is of sentiment or of action; on the other side; counter to; in contrariety to; hence, adverse to
4. prep. Archaic or Dial. By of before the time that; in preparation for; so as to be ready for the time when.