In a state of secrecy or minimal public knowledge; known only by a select few people. I need to tell you some important news, but it has to be hush-hush for a while.Apparently it's hush-hush, but I just found out John and Tracey are getting married soon!
hush-hush
(ˈhəʃˈhəʃ)
1. mod. secret; undercover. The matter is so hush-hush I can’t talk about it over the phone.
2. mod. secretly. They did it so hush-hush that no one knew for a long time.