a private or secret place known only to a few people
King revealed the inner core of Deep Throat as a self-assured man who had no regrets.
It was his inner core that made him a torchbearer of ideals.
When living trees are chosen, the inner core, or heart of the tree, is usually more or less decayed.
This inner core is much the same sort of work as the masonry in the pueblos of Arizona.
A facing was put on over this inner core, which served both for ornament and for strength.
In this type the inner core burns quite slowly at the rate of two or three feet to the minute.
The sensing unit was in an inner core, surrounded by an atmosphere of pressurized helium.
And here in one glowing sentence the inner core of evolution lay revealed.