in the know

in the know  {adj. phr.},  {informal}
Knowing about things that most people do not know about; knowing secrets or understanding a special subject.
Tina helped Professor Smith make some of the exam questions, and she felt important to be in the know.
In a print shop, Mr. Harvey is in the know, but in a kitchen he can't even cook an egg.
Compare: GET WISE. Contrast: IN THE DARK.
Categories: adjective informal