Honestly; in a frank. From the Frankish people of medieval West Germany and France, and one of many Germanic federations.
Is often used by bourgeois elitists in attempt at appearing intelligent. Almost always said after "quite" and sometimes in a sentence with "rather", two other completely useless words.
"Quite frankly, Mater, I found the performance to be rather dull."
A word used as a license to ignore all political correctness and allow you to say whatever you damnwell want, regardless of who you offend and whether or not they are right in front of you.
.... and frankly, I don't think Peter is capable of doing his job. Oh hi Pete....