Old English

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The English language from the middle of the 5th to the beginning of the 12th century.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• proper noun linguistics, history The ancestor language of Modern English, also called Anglo-Saxon, spoken in most of Britain from about 400 to 1100.
• proper noun nonstandard Archaic English or Middle English speech or writing, or an imitation of this: old English.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun English prior to about 1100