Clued-in 

Opposite of "Clueless."

Knowing, in the loop; in possession of the right information.

His mother thought she was Clued-in, but she really knew nothing about what the kids were doing.

Clued-in by WriteNow November 23, 2009

Clue in 

To pick up on or sense another’s thought. Usually based on a. knowledge of the person or type of person and context of the situation and b. the ability to read body signals.

The ability to catch on to something without knowing the background.

Entering a conversation midstream and understanding immediately the gist of it.

I knew what he was going to say that, I just sort of “clue in”.

Clue in by UWB is really not me February 4, 2010