Aguefort's Censorship

The instant you see or hear something, you may flick your wrist and cover it with an opaque black rectangle.  This rectangle is illusory, but moves with the target it is covering.  The rectangle is 2-dimensional, and no longer than 2 feet in any direction, but it covers the target from every visual angle.

If it is cast to obscure words (such as swears), the rectangle appears over the individual's mouth and the sound of the word is muffled by a startling beep.  It vanishes after the word or phrase ends, but you can use your reaction to cause the censorship to reappear anytime before the spell ends if an individual continues to speak in a way you wish to obscure.