reticence

The fact or character of being reticent; a disposition to keep, or the keeping of, one's own counsel; the state of being silent; reservation of one's thoughts or opinions.

In rhetoric, aposiopesis.

The quality or state of being reticent, or keeping silence; the state of holding one's tonque; refraining to speak of that which is suggested; uncommunicativeness.

A figure by which a person really speaks of a thing while he makes a show as if he would say nothingon the subject.

Tight-lippedness, discretion, avoidance of saying too much.