This just in from a reader, with the scan labeled 'lexical category confusion'.
I think the character here is 'Billy', judging from here. Of course, it's anything but weird: we all know that verb is a verb and, yeah OK, also a noun. Is it a prescriptivist jab at verbing? Another strip, Calvin & Hobbes, is where verbal verb is usually seen as having taken off, and that's no longer being written/drawn. It surely can't be a jab at them, can it? Maybe verbing is acquired after age 7, apparently Billy's age. Whatevs.
Hat tip to P.R.