Definitions by Web MD Bitch

Diphtheria 

An awful disease that causes the person affected by it to have trouble reading and often inhibits their ability to learn.

Dylan: Wow, man, did you hear Jeff has diphtheria?
Joey: Shit, that's tough. How's he gonna get through school?
Dylan: I don't know, man.
Dani: Let's just all be thankful he doesn't have dyslexia.

Diphtheria by Web MD Bitch June 10, 2011