The stage of the Egyptian language used from roughly 2240-1990 B.C., surviving as a 'classical' variant down to Roman times. It is in the Hamito-semitic family, distantly related to Hebrew and Babylonian, wherein most words are formed from a triliteral stem, and is written in hieroglyphs. The language is known for its concrete realism, and inability to express concepts such as probability or hypothetical statements.
For anyone who actually wants to give a crack at this language, here's a small bibliography:

Gardiner, Alan. Egyptian Grammar: Being an Introduction to the Study of Hieroglyphs, 3rd Edition. (Oxford, 1994). This is the only real reference grammar for Middle Egyptian, though it is rather outdated; it is still somewhat correct, and has hordes of examples. If you stick with it, you'll own it eventually.

Allen, James. Middle Egyptian: An Introduction to the Language and Culture of Hieroglyphs. (Cambridge, 2000). A decent little book, interspersing little cultural chapters with his grammatical lessons; the most recent one in English, and the easiest to work through on your own. He has several rather bizarre theories about grammar and language (what can I say? he works at the met), and much of the book is controversial (He tries to invent forms and remove others from standard theory without a real logical basis or explanation).

Faulkner, Raymond. A Concise Dictionary of Middle Egyptian. (Oxford, 1996). The only English portable dictionary of Middle Egyptian, though also outdated both in the transcriptions (the word for treasurer comes to mind) and some of the translations. Mostly correct.