A historical region of north-central Europe including present-day northern Germany and Poland. Its ancient, Baltic-speaking inhabitants were conquered by the Teutonic Knights in the 1200s. West Prussia was ceded to Poland in 1466, and East Prussia became a Polish fief that passed to Brandenburg in 1618. Proclaimed a kingdom in 1701, Prussia became a military power under Frederick II (reigned 1740-1786). Prussia was instrumental in the unification of Germany, and in 1871 its king was declared Kaiser Wilhelm I of Germany.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.