If you come across a word or phrase in another language, a printed or online dictionary is usually a good place to look for help. If you're faced with a language that's long been dead, however, then you've got problems. Those studying the cuneiform texts of Mesopotamian clay tablets or stone carvings now have reason to rejoice. After nine decades, the University of Chicago's Assyrian Dictionary Project has finally been completed - opening an encyclopedic window into the day to day lives of people from one of the world's first civilizations.

Originally started in 1921 by the founder of the University of Chicago's Oriental Institute - James Henry Breasted - the 21 volume Chicago Assyrian Dictionary brings together millions of index cards that help to explain the usage of the 28,000 words used by Babylonians, Assyrians and others in Mesopotamia between 2500 B.C. and A.D. 100.

Each word can have several meanings, perhaps depending on the context in which it was used. Not long after the start of the vast undertaking, scholars discovered that the Assyrian language - after which the dictionary was named - was in fact a dialect of Akkadian, the earliest known Semitic language. The project was therefore expanded to include all the various dialects of the ancient language.

"The Assyrian Dictionary is the single most impressive effort I know of to systematically record, codify and make accessible the Akkadian language that forms the heart of the textual record of civilization in the place of its birth: Mesopotamia," said Gil Stein, director of the Oriental Institute. "The Assyrian Dictionary is not simply a word list. By detailing the history and range of uses of each word, this unique dictionary is in essence a cultural encyclopedia of Mesopotamian history, society, literature, law and religion and is an indispensable research tool for any scholar anywhere who seeks to explore the written record of Mesopotamian civilization."

The Institute's Robert Biggs - who, in addition to working on the dictionary, has also uncovered Assyrian tablets at archeological digs in the Near East - says that the language wasn't the exclusive domain of kings and queens. Tablets have been unearthed which discuss the everyday lives of common folk, too.

"They wrote these tablets thousands of years ago, never meaning for them to be read so much later, but they speak to us in a way that makes their experiences come alive," says Biggs. "You'd brush away the dirt, and then there would emerge a letter from someone who might be talking about a new child in the family, or another tablet that might be about a loan until harvest time."

The published sets will now be sold mostly to university libraries.