Aim at = To direct the intention or purpose; to attempt the accomplishment of a purpose; to try to gain; to endeavor; intention; purpose; design; scheme.
Example: I aimed at the public's heart, and by accident I hit it in the stomach.
Usage in Sentence: Aim at, not on or against.
Don’t say: She aimed on (or against) the target.
Say: She aimed at the target.
Note: Use the preposition at to denote direction: throw at, shout at, fire at, shoot at. Shoot (without the at) means to kill: He shot a bird (= he hit and killed it).