1. In a direction or course opposite to: row against the current.
2. So as to come into forcible contact with: waves dashing against the shore.
3. In contact with so as to rest or press on: leaned against the tree.
4. In hostile opposition or resistance to: struggle against fate.
5. Contrary to; opposed to: against my better judgment.
6. In competition with: raced against the record holder.
7. In contrast or comparison with the setting or background of: dark colors against a fair skin.
8. In preparation for; in anticipation of: food stored against winter.
9. As a defense or safeguard from: protection against the cold.
10. To the account or debt of: drew a check against my bank balance.
11. Directly opposite to; facing.
[Middle English, alteration of againes, from Old English ongeagn.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.