Downright lying or Outright lying?

differencessynonymsword-choice

I'd like to describe that someone is lying explicitly without any shame. 
Someone who lies and knows that they are lying and knows that others know
but they don't care. 
Should I say downright or outright lying?

Best Answer

The word ‘downright’ matches closer to your intended emphasis of “without shame”; as compared to ‘outright’ which emphasizes abruptness without any hesitation that (possibly )was due, while also typically suggesting (to a lower degree than the former term) that doing the thing at-all is wrong.

My source of reference is everyday American English. If you search various definitions then you probably shall find that 'downright' specifically has a negative connotation and in common usage is preceded by some ostensibly-bad quality or thing (e.g. "downright ugly") , whereas 'outright' is not as explicitly meant disfavorably (as it can in some instances be beneficial or at least neutral sans broader context, e.g. "outright told me" implying "didn't wait to tell me" as opposed to "quick to give a blunt comment" ---unlike 'downright' which very seldom that would be the case, i.e. "downright joyful" is uncommon if not implicitly oxymoronic).