I read from dip to diphyodont.

Diphosgene was originally made for chemical warfare. Not cool. 

https://en.wikipedia.org/wiki/Diphosgene

Diphteria sounds pretty terrible but there is a vaccine! Yay Science!

https://en.wikipedia.org/wiki/Diphtheria

I guess "diphyletic" is the same as "paraphyletic" which my brain is currently having a hard time grasping. So many words! 

https://en.wikipedia.org/wiki/Paraphyly

Humans are Diphyodonts!

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