Effrontery
Etymology
From French effronterie, from effronté, "shameless," which traces to Late Latin effrons, "barefaced": "ex-," out or without, plus frons, "forehead, brow." The image is of a face that will not color or flinch — no blush rising to the brow to betray a sense of shame. To have effrontery is, literally, to be without that telltale forehead.
noun · /ih-FRUN-tuh-ree/
Shameless, insolent boldness — audacity that flouts propriety without a trace of embarrassment.
What it names
The nerve of someone who does the outrageous thing openly and without blushing, as if the usual rules of shame did not apply.
Example
He had the effrontery to ask for a reference from the firm he had just been fired from for theft.
Related idea
Audacity can be admirable daring; effrontery is its graceless cousin — boldness that has crossed into shameless insolence.