I chastise my students when they cite dictionary definitions in their papers. Mostly, I do this because it gives them a false sense of security and blinds them to the processes of how meaning is created and how power is reproduced. (It also often signals that they haven't been doing the assigned reading and/or listening in class.) Turns out, they're in good company, though. The Justices of the SCotUS have been relying more and more on dictionaries over the past two decades. That just seems lazy to me.