Obvious spoken or written idiocy for which frustration on the part of the receiving party is only slightly quelled by the laughable and simple-minded nature of the offense. Derption is immediately apparent to all but the derp demonstrating their derptitude.
"Did you see Zuckerberg testify in front of Congress? The derption in the questions they asked him was almost unbelievable... even for them."
Fogey/fogy /fougi/ sl. (early 18C+, orig. Scot) old-fashioned, stuck-in-the mud.
Person with old fashioned ideas which he is unwilling to change: Come to the disco and stop being such an old fogey!
You think me an old fogeyand an old tory, his thoughtful voice said. I saw three generations since O’Connel’s time. I remember the famine. Do you know that the orange lodges agitated for repeal of the union twenty years before O’Connel did or before the prelates of your communion denounced him as a demagogue? You fenians forget some things. (James Joyce, Ulysses. PenguinBooks,1992. p. 38)