nerve-center (noun) nerve center: center of activity
Sinonime: buttoning one's lip, buttoning up, clamming up, close-lipped, closemouthed,
hidden, hush-hush, mum's the word, on the Q. T.,
private, reticent, retired,
secluded, secretive, silent, taciturn, tight chops, tight-lipped, uncommunicative, unforthcoming, zipping one's lips
Antonime: open, unreserved