Are you dern?

Funny how language works! Take this one, for instance:

Dern
Of persons, proceeding in secret or in the dark; kept concealed; hence of evil or deceitful nature. Of persons, secret in purpose or action; reserved; hence, underhanded. sly, crafty.  Of a person, treated as a confidant; entrusted with hidden matters. Of places, serving well to conceal, as lying out of the way.

Sir James Murray, New English Dictionary, 1897