1. In opposition; noting enmity or disapprobation.
His hand will be against every man. Gen 16.
I am against your pillows. Ezek 8.
2. In opposition, noting contrariety, contradiction, or repugnance; as, a decree against law, reason or public opinion.
3. In opposition, noting competition, or different sides or parties; as, there are twenty votes in the affirmative against ten in the negative.
4. In an opposite direction; as, to ride against the wind.
5. Opposite in place; abreast; as, a ship is against the mouth of a river. In this sense it is often preceded by over.
Aaron lighted the lamps over against the candlesticks.
6. In opposition, noting adversity, injury, or contrariety to wishes; as, this change of measures is against us.
7. Bearing upon; as, one leans against a wall.
8. In provision for; in preparation for.
Urijah made it against king Ahaz came from Damascus.
2 Ki 16.
In this sense against is a preposition, with the following part of the sentence for an object. See , prep. def. 2.
In short, the sense of this word is opposition, variously modified according to its application to different objects.