The Oxford English Dictionary definition for dumb (7b) is “Foolish, stupid, ignorant (chiefly of persons)”. This episode would have been better had Beverly just read random entries out of the OED for an hour rather than having to witness this lousy episode. What the producers should have done upon seeing a script involving a Scottish “ghost” that has haunted the Crusher family for generations, they should have said “Welp, let’s just stop making episodes because we’re officially out of ideas.” Everyone involved in this episode ought to be ashamed of themselves.