hint at (something)
To indirectly suggest or insinuate something. And what exactly are you hinting at? If you have something to say, just say it! I tried hinting at my interest in Joe, but he's just not picking up any of my signals.
hint at something
to refer to something; to insinuate something. What are you hinting at? I am not hinting at anything. I am telling you to do it!