drive at (something)
To allude to some point or topic or orient one's discussion of something toward a particular conclusion. What exactly are you driving at with a critical statement like that? If you have a problem with my work, just tell me.
drive at something
to be making a point; to be hinting at something; to work up to making a point. What are you driving at? What's the point? I could tell Mary was driving at something, but I didn't know what it was.
drive at
Mean to do or say, as in I don't understand what he's driving at. Today this idiom, first recorded in 1579, is used mainly with the participle driving.
drive at
v. To mean to do or say something; have something as a point: I don't understand what you're driving at—just tell me what you mean.