What is Foggy ?
Foggy is (adj) 1. covered in fog It’s often foggier than this in November. They drove slowly along the foggy streets. It’s dangerous to drive fast when it’s foggy. 2. not to have the foggiest (idea) to know nothing at all (informal.) She hadn’t the foggiest idea how to get to the airport. (NOTE: foggier foggiest)
source: Easier English, Student Dictionary Upper Intermediate Level