aposiopesy

APOSIO'PESY, n. [Gr. of to be silent.]

Reticence or suppression; as when a speaker for some cause, as fear, sorrow, or anger, suddenly breaks off his discourse, before it is ended; or speaks of a thing, when he makes a show as if he would say nothing on the subject; or aggravates what he pretends to conceal, by uttering a part and leaving the remainder to be understood.